Rubber composition containing phosphite ester and use thereof

Abstract

To improve abrasion resistance of a vulcanized rubber composition without significantly impairing fuel economy (particularly rolling resistance characteristics) thereof.SOLUTION: A rubber composition contains a rubber component, a vulcanization accelerator, silica, and a compound represented by formula (1) [where each R1 independently represents a -C15H25-31 group; each R2 independently represents a hydrogen atom or a hydroxyl group; and each R3 independently represents a hydrogen atom or a methyl group].SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to rubber compositions containing phosphites and uses thereof. [Background technology]

[0002] Fuel economy is one of the important performance characteristics of tires, and there is a demand for improving fuel economy. For example, Patent Document 1 describes that the use of a disulfide compound such as 4,4'-dipyridyl disulfide improves the low heat generation property of a rubber composition, thereby improving the fuel economy of the rubber composition.

[0003] Furthermore, Patent Document 2 describes the use of a pyrimidine derivative (particularly, 2,2-bis(4,6-dimethylpyrimidyl)disulfide) to achieve hardness stabilization of a vulcanized rubber composition (more specifically, suppressing an increase in hardness due to aging of the vulcanized rubber composition). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-18716 A [Patent Document 2] Special Publication No. 2004-500471 Summary of the Invention [Problem to be solved by the invention]

[0005] Abrasion resistance is an important performance of a tire, as is the above-mentioned fuel economy. However, fuel economy and abrasion resistance are in a trade-off relationship, and improving one of them reduces the other. The present invention has been made in light of such circumstances, and its object is to improve the abrasion resistance of a vulcanized rubber composition without significantly impairing its fuel economy (particularly, rolling resistance characteristics). [Means for solving the problem]

[0006] As a result of intensive research aimed at solving the above problems, the present inventors have arrived at the present invention. That is, the present invention provides the following preferred embodiments.

[0007] [1] A rubber component, a vulcanization accelerator, silica, and a copolymer of the formula (1): [ka] [In the formula, R1 is independently -C 15 H 25-31 represents a group, R2 each independently represents a hydrogen atom or a hydroxyl group; R3 each independently represents a hydrogen atom or a methyl group. A rubber composition comprising a compound represented by the formula: [2] Equation (2): [ka] [In the formula, R1 is independently -C 15 H 25-31 represents a group, R2 each independently represents a hydrogen atom or a hydroxyl group; R3 each independently represents a hydrogen atom or a methyl group; * represents a bond. The rubber composition according to [1], further comprising an oligomer (B) having a structure represented by the following formula: [3] The rubber composition according to [2], wherein the oligomer (B) has a number average molecular weight of 1,900 to 30,000. [4] The oligomer (B) has the formula (3): [ka] [In the formula, R1 is independently -C 15 H 25-31 represents a group, R2 each independently represents a hydrogen atom or a hydroxyl group; R3 each independently represents a hydrogen atom or a methyl group. The rubber composition according to [2] or [3], comprising a compound represented by the following formula: [5] The oligomer (B) has the formula (4): [ka] [In the formula, R1 is independently -C 15 H 25-31 represents a group, R2 each independently represents a hydrogen atom or a hydroxyl group; R3 each independently represents a hydrogen atom or a methyl group. The rubber composition according to any one of [2] to [5], comprising a compound represented by the following formula: [6] The rubber composition according to any one of [1] to [5], further comprising an amine compound (A) having a hydroxyalkyl group. [7] The rubber composition according to [6], wherein the amine compound (A) is an alkanolamine. [8] The alkanolamine has formula (I): [ka] [In formula (I), Y 1 , Y 2 and Y 3 each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms and at least one hydroxyl group, provided that Y 1 ~Y 3 at least one of represents an alkyl group having 1 to 8 carbon atoms and having at least one hydroxyl group. Or, a compound of formula (II): [ka] [In formula (II), Y 4 , Y 5 , Y 6 and Y 7each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms and at least one hydroxyl group, provided that Y 4 ~Y 7 at least one of represents an alkyl group having 1 to 8 carbon atoms and having at least one hydroxyl group, and B represents an alkylene group having 1 to 4 carbon atoms. The rubber composition according to [7], [9] The rubber composition according to [7] or [8], wherein the alkanolamine is represented by formula (I):

[10] Y in formula (I) 1 , Y 2 and Y 3 And Y in formula (II) 4 , Y 5 , Y 6 and Y 7 each independently represents -CH2-CH(OH)-R6 [wherein R6 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms].

[11] The rubber composition according to any one of [1] to

[10] , wherein the rubber component contains a diene rubber.

[12] The rubber composition according to any one of [1] to

[11] , wherein the rubber component contains a styrene-butadiene copolymer rubber.

[13] The rubber composition according to any one of [1] to

[12] , wherein the vulcanization accelerator includes a sulfenamide vulcanization accelerator.

[14] The rubber composition according to any one of [1] to

[13] , further comprising carbon black.

[15] The rubber composition according to any one of [1] to

[14] , further comprising a sulfur component.

[16] A vulcanized rubber composition obtained by vulcanizing the rubber composition described in

[15] .

[17] A tire comprising the vulcanized rubber composition according to

[16] .

[18] For improving the abrasion resistance of a vulcanized rubber composition containing silica, a compound represented by the formula (1): [ka] [In the formula, R1 is independently -C 15H 25-31 represents a group, R2 each independently represents a hydrogen atom or a hydroxyl group; R3 each independently represents a hydrogen atom or a methyl group. Use of a compound represented by the formula: Effect of the Invention

[0008] According to the present invention, it is possible to improve the abrasion resistance of a vulcanized rubber composition without significantly impairing its fuel economy (particularly, rolling resistance characteristics). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention. Note that, hereinafter, the "compound represented by formula (1)" may be abbreviated as "compound (1)". Compounds represented by other formulas may also be abbreviated in the same manner.

[0010] The present invention provides the following: (1) a rubber composition comprising a rubber component, a vulcanization accelerator, silica, compound (1), and other components as required; (2) a rubber composition comprising a rubber component, a vulcanization accelerator, silica, compound (1), a sulfur component, and other components as necessary; (3) a vulcanized rubber composition obtained by vulcanizing the rubber composition of (2), (4) A tire comprising the vulcanized rubber composition of (3). (5) Use of compound (1) for improving the abrasion resistance of a vulcanized rubber composition containing silica.

[0011] <Definition> First, the definitions of the substituents and the like used in this specification will be explained in order. "C x-y " means that the number of carbon atoms is x or more and y or less (x and y represent numbers).

[0012] Examples of halogen atoms include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0013] The alkyl group may be either linear or branched. The number of carbon atoms in the alkyl group is, for example, 1 to 18. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a 1-ethylpropyl group, a hexyl group, an isohexyl group, a 1,1-dimethylbutyl group, a 2,2-dimethylbutyl group, a 3,3-dimethylbutyl group, a 2-ethylbutyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group.

[0014] The alkyl group may have a substituent. Other groups that contain an alkyl group as a part (e.g., an alkoxy group) may also have a substituent. The alkyl group (e.g., C 1-18 alkyl group) and alkyl groups as a moiety (e.g., C 1-18 Substituents that other groups, including alkyl groups, may have include, for example, the following: (1) a halogen atom, (2) a cycloalkyl group (preferably C 3-8 cycloalkyl group), (3) an alkoxy group (preferably C 1-6 alkoxy group), (4) Cycloalkyloxy group (preferably C 3-8 cycloalkyloxy group), (5) Aryloxy group (preferably C 6-14 aryloxy group), (6) Aralkyloxy group (preferably C 7-16 aralkyloxy group), (7) An amino group which may have a substituent.

[0015] The number of carbon atoms in the cycloalkyl group is, for example, 3 to 10. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a bicyclo[2.2.1]heptyl group, a bicyclo[2.2.2]octyl group, a bicyclo[3.2.1]octyl group, and an adamantyl group.

[0016] The number of carbon atoms in the aryl group is, for example, 6 to 18. Examples of the aryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, and a 9-anthryl group.

[0017] The number of carbon atoms in the aralkyl group is, for example, 7 to 20. Examples of the aralkyl group include a benzyl group, a phenethyl group, a naphthylmethyl group, and a phenylpropyl group.

[0018] The cycloalkyl group, the aryl group and the aralkyl group may all have a substituent. Other groups that contain a cycloalkyl group as a part (e.g., a cycloalkyloxy group) may also have a substituent. The cycloalkyl group (e.g., C 3-10 cycloalkyl groups), aryl groups (e.g., C 6-18 Aryl groups) and aralkyl groups (e.g., C 7-20 Examples of substituents that may be carried by the aryl groups (aralkyl groups), as well as other groups that contain these groups as part thereof, include the following: (1) a halogen atom, (2) an alkyl group (preferably C 1-6 alkyl group), (3) a cycloalkyl group (preferably C 3-8 cycloalkyl group), (4) an aryl group (preferably C 6-14 aryl group), (5) Aralkyl groups (preferably C 7-16 aralkyl groups), (6) an alkoxy group (preferably C 1-6 alkoxy group), (7) Cycloalkyloxy group (preferably C3-8 cycloalkyloxy group), (8) Aryloxy group (preferably C 6-14 aryloxy group), (9) Aralkyloxy group (preferably C 7-16 aralkyloxy group), (10) An amino group which may have a substituent.

[0019] The alkyl group that is a part of the alkoxy group (i.e., alkyloxy group) is as described above. The alkyl group that is a part of the group described below is also the same. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group.

[0020] The cycloalkyl group that is a part of the cycloalkyloxy group is as described above. The same applies to the cycloalkyl group that is a part of the group described below. Examples of the cycloalkyloxy group include a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, and a cyclooctyloxy group.

[0021] The aryl group that is a part of the aryloxy group is as described above. The same applies to the aryl group that is a part of the group described below. Examples of the aryloxy group include a phenyloxy group, a 1-naphthyloxy group, and a 2-naphthyloxy group.

[0022] The aralkyl group that is a part of the aralkyloxy group is as described above. The aralkyl group that is a part of the group described below is also the same. Examples of the aralkyloxy group include a benzyloxy group, a phenethyloxy group, a naphthylmethyloxy group, and a phenylpropyloxy group.

[0023] Examples of the alkyl-carbonyloxy group include an acetyloxy group, a propanoyloxy group, a butanoyloxy group, a 2-methylpropanoyloxy group, a pentanoyloxy group, a 3-methylbutanoyloxy group, a 2-methylbutanoyloxy group, a 2,2-dimethylpropanoyloxy group, a hexanoyloxy group, and a heptanoyloxy group. 1-18 The term "alkyl-carbonyloxy group" means that the alkyl group that is a part of this group has a carbon number of 1 to 18. Other descriptions have similar meanings.

[0024] Examples of the cycloalkyl-carbonyloxy group include a cyclopropyl-carbonyloxy group, a cyclobutyl-carbonyloxy group, a cyclopentyl-carbonyloxy group, a cyclohexyl-carbonyloxy group, a cycloheptyl-carbonyloxy group, and a cyclooctyl-carbonyloxy group.

[0025] Examples of the aryl-carbonyloxy group include a benzoyloxy group, a 1-naphthoyloxy group, and a 2-naphthoyloxy group.

[0026] Examples of the aralkyl-carbonyloxy group include a phenylacetyloxy group and a phenylpropionyloxy group.

[0027] Examples of the alkoxy-carbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a butoxycarbonyl group, an isobutoxycarbonyl group, a sec-butoxycarbonyl group, a tert-butoxycarbonyl group, a pentyloxycarbonyl group, and a hexyloxycarbonyl group.

[0028] Examples of cycloalkyloxy-carbonyl groups include a cyclopropyloxycarbonyl group, a cyclobutyloxycarbonyl group, a cyclopentyloxycarbonyl group, a cyclohexyloxycarbonyl group, a cycloheptyloxycarbonyl group, and a cyclooctyloxycarbonyl group.

[0029] Examples of the aryloxy-carbonyl group include a phenyloxycarbonyl group, a 1-naphthyloxycarbonyl group, and a 2-naphthyloxycarbonyl group.

[0030] Examples of the aralkyloxy-carbonyl group include a benzyloxycarbonyl group, a phenethyloxycarbonyl group, a naphthylmethyloxycarbonyl group, and a phenylpropyloxycarbonyl group.

[0031] Examples of the optionally substituted carbamoyl group include a carbamoyl group which may have one or two substituents selected from an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, and an optionally substituted aralkyl group.

[0032] Preferable examples of the optionally substituted carbamoyl group include the following: (1) a carbamoyl group, (2) a mono- or di-(optionally substituted alkyl)carbamoyl group (e.g., a methylcarbamoyl group, an ethylcarbamoyl group, a dimethylcarbamoyl group, a diethylcarbamoyl group, or an N-ethyl-N-methylcarbamoyl group), (3) a mono- or di-(optionally substituted cycloalkyl)carbamoyl group (e.g., a cyclopropylcarbamoyl group, a cyclohexylcarbamoyl group), (4) a mono- or di-(aryl which may have a substituent)carbamoyl group (e.g., a phenylcarbamoyl group), (5) A mono- or di-(aralkyl which may have a substituent)carbamoyl group (e.g., a benzylcarbamoyl group, a phenethylcarbamoyl group). Here, the term "mono- or di-(optionally substituted alkyl)carbamoyl group" refers to a mono(optionally substituted alkyl)carbamoyl group or a di(optionally substituted alkyl)carbamoyl group. The same applies to others. In addition, the term "mono(optionally substituted alkyl)carbamoyl group" refers to a carbamoyl group having an optionally substituted alkyl group as one substituent. The same applies to others.

[0033] Examples of the amino group which may have a substituent include an amino group which may have one or two substituents selected from an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, an aralkyl group which may have a substituent, an alkyl-carbonyl group which may have a substituent, a cycloalkyl-carbonyl group which may have a substituent, an aryl-carbonyl group which may have a substituent, and an aralkyl-carbonyl group which may have a substituent.

[0034] Preferable examples of the amino group which may have a substituent include the following: (1) an amino group, (2) a mono- or di-(optionally substituted alkyl)amino group (e.g., a methylamino group, a trifluoromethylamino group, a dimethylamino group, an ethylamino group, a diethylamino group, a propylamino group, or a dibutylamino group), (3) a mono- or di-(optionally substituted cycloalkyl)amino group (e.g., a cyclopropylamino group, a cyclohexylamino group), (4) a mono- or di-(aryl)amino group (e.g., a phenylamino group), (5) a mono- or di-(aralkyl which may have a substituent)amino group (e.g., a benzylamino group, a dibenzylamino group), (6) a mono- or di-(optionally substituted alkyl-carbonyl)amino group (e.g., an acetylamino group, a propionylamino group), (7) a mono- or di-(optionally substituted cycloalkyl-carbonyl)amino group (e.g., a cyclopropylcarbonylamino group, a cyclohexylcarbonylamino group), (8) a mono- or di-(optionally substituted aryl-carbonyl)amino group (e.g., a benzoylamino group), (9) A mono- or di-(aralkylcarbonyl)amino group which may be substituted (e.g., a benzylcarbonylamino group). Here, the term "mono- or di-(optionally substituted alkyl)amino group" refers to a mono(optionally substituted alkyl)amino group or a di(optionally substituted alkyl)amino group. The same applies to others. Furthermore, the term "mono(optionally substituted alkyl)amino group" refers to an amino group having an alkyl group, which may be substituted, as one substituent. The same applies to others.

[0035] <Compound represented by formula (1)> The present invention relates to a compound represented by formula (1): [ka] One of the features of the present invention is to use a compound represented by the following formula: The compound (1) may be of one type or of two or more types.

[0036] In formula (1), each R1 is independently -C 15 H 25-31 each R2 independently represents a hydrogen atom or a hydroxyl group, and each R3 independently represents a hydrogen atom or a methyl group.

[0037] In formula (1), each R1 is independently -C 15 H 25-31 groups, which may be the same or different. 15 H 25-31 The group is a linear hydrocarbon group having 0 to 3 double bonds, and is, for example, a group represented by the following formulas (R1-1) to (R1-4): [ka] Examples of the group include a group represented by the following formula:

[0038] In formula (1), each R2 independently represents a hydrogen atom or a hydroxyl group. R2 in formula (1) may be the same or different.

[0039] In formula (1), each R3 independently represents a hydrogen atom or a methyl group. R3 in formula (1) may be the same or different.

[0040] In one embodiment of the present invention, the compounds (1) contained in the rubber composition may be the same or different from each other.

[0041] In one embodiment of the present invention, the molecular weight of compound (1) is preferably 923 to 1032. The polystyrene-equivalent molecular weight of compound (1) determined by gel permeation chromatography (hereinafter also referred to as GPC) measurement is preferably 1080 or more and less than 1820.

[0042] The amount of compound (1) (when two or more kinds of compound (1) are used, the total amount thereof) is, from the viewpoint of improving abrasion resistance without significantly impairing fuel economy, 0.02 to 10 parts by mass, preferably 0.02 to 8 parts by mass, more preferably 0.1 to 6 parts by mass, and further preferably 0.1 to 5 parts by mass, per 100 parts by mass of the rubber component.

[0043] The present inventors have found that when a rubber composition contains compound (1), its abrasion resistance is improved without significantly impairing fuel economy. Although the reason for this is unclear, it is believed that the interaction between compound (1) and silica or the like improves the dispersibility of fillers such as silica in the composition, improving reinforcing properties and thus improving the abrasion resistance.

[0044] <Oligomer (B)> From the viewpoint of further improving fuel economy and wear resistance, the rubber composition of the present invention preferably further contains, in addition to the compound (1), an oligomer (B) derived from the compound (1). The oligomer (B) has a high phosphorus concentration per unit weight, and therefore can contribute to improving fuel economy and wear resistance.

[0045] In the present invention, the oligomer (B) derived from the compound (1) includes a compound containing two or more phosphite structures and 2n+1 (n represents the number of phosphite structures, n is an integer of 2 or more), i.e., 5 or more, benzene ring structures contained in the compound (1), and a mixture of such compounds. The benzene ring structure contained in the compound (1) is, for example, represented by the formula (Z): [ka] [In formula (Z), R a represents R2 or a bond, * represents a bond, and R1 to R3 are the same as R1 to R3 in formula (1). It may be a structure represented by:

[0046] In one embodiment of the present invention, the rubber composition of the present invention comprises: Formula (2): [ka] [In the formula, R1 is independently -C 15 H 25-31 represents a group, R2 each independently represents a hydrogen atom or a hydroxyl group; R3 each independently represents a hydrogen atom or a methyl group; * represents a bond. It is preferable that the copolymer further contains an oligomer (B) containing a structure represented by the following formula:

[0047] In the present invention, the oligomer (B) includes a compound in which three benzene ring structures are linked to one phosphite ester structure, in other words, a compound in which a phosphite ester structure and a benzene ring structure contained in the compound (1) are linked alternately, or a compound in which a benzene ring structure contained in the compound (1) is linked via a phosphite ester structure. Such a compound includes, for example, a compound represented by the formula (E): [ka] [In the formula (E), T is a structure M or structure N represented by the formula (M) or formula (N): [ka] [In formulas (M) and (N), * represents a bond bonded to the oxygen atom in formula (E), T represents structure M or structure N, and R1 to R3 are the same as R1 to R3 in formula (1)] and at least one of the three T's in formula (E) is a structure N. The compound may be represented by the formula:

[0048] In the present invention, among the oligomers (B), those having two phosphite structures are sometimes referred to as dimers, those having three phosphite structures are sometimes referred to as trimers, and those having n phosphite structures are sometimes referred to as n-mers. Furthermore, the oligomer (B) includes, for example, a compound in which at least one of the three benzene rings contained in the compound (1) is further bonded to the benzene ring Z contained in the compound (1) via a phosphite ester group, and also includes, in some cases, a compound in which a further benzene ring Z is bonded to the bonded benzene ring via a phosphite ester group, and similarly, a compound in which benzene rings Z are bonded via phosphite ester groups up to an n-mer. The benzene ring Z may be a benzene ring represented by the above formula (Z).

[0049] In one embodiment of the present invention, the oligomer (B) preferably contains a dimer from the viewpoint of improving the abrasion resistance of the vulcanized rubber composition without significantly impairing the fuel economy of the vulcanized rubber composition. [ka] [In the formula, R1 to R3 are the same as R1 to R3 in formula (1)] Examples of the compound include compounds represented by the following formula:

[0050] In one embodiment of the present invention, the oligomer (B) preferably contains a trimer from the viewpoint of improving the abrasion resistance of the vulcanized rubber composition without significantly impairing the fuel economy of the vulcanized rubber composition. [ka] [In the formula, R1 to R3 are the same as R1 to R3 in formula (1)] Examples of the compound include compounds represented by the following formula:

[0051] In one embodiment of the present invention, the oligomer (B) may include a tetramer and an n-mer having tetramer or more. The n-mer having tetramer or more may not contain a branch or may contain a branch. For example, in the case of a tetramer, it may be a compound having no branch represented by formula (5) or a compound having a branch represented by formula (6). [ka] [ka] [In the formula, R1 to R3 are the same as R1 to R3 in formula (1)]

[0052] The number of monomers contained in oligomer (B) can be confirmed by GPC analysis. For example, in the case of a dimer, if a peak is observed in the range of polystyrene-equivalent molecular weight of 1820 or more and less than 2500 in GPC analysis, it can be said that oligomer (B) contains a dimer. Similarly, in the case of a trimer, if a peak is observed in the range of polystyrene-equivalent molecular weight of 2500 or more and less than 3200 in GPC analysis, it can be said that oligomer (B) contains a trimer.

[0053] In the present invention, the number average molecular weight of the oligomer (B) is preferably 1,900 to 30,000. When the number average molecular weight of the oligomer (B) is within the above range, the abrasion resistance of the vulcanized rubber composition can be improved without significantly impairing the fuel economy. The number average molecular weight of the oligomer (B) is preferably 2,000 or more, more preferably 2,200 or more, and preferably 20,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, and even more preferably 3,000 or less. When the number average molecular weight of the oligomer (B) is the above lower limit or more and the above upper limit or less, the abrasion resistance of the vulcanized rubber composition can be further improved without significantly impairing the fuel economy of the vulcanized rubber composition. The number average molecular weight of the oligomer (B) can be determined by GPC measurement and conversion into standard polystyrene.

[0054] In one embodiment of the present invention, the compound (1) and oligomer (B) contained in the rubber composition of the present invention are preferably derived from a cashew oil extract from the viewpoint of increasing the safety of the rubber composition and from the viewpoint of effective utilization of resources since the compound (1) and oligomer (B) are inedible parts. Examples of the cashew oil extract include cardanol, curdle, and methyl curdle contained in cashew oil. In addition, in the present invention, the compound (1) and oligomer (B) being derived from a cashew oil extract means that the compound (1) and oligomer (B) are prepared using cardanol, curdle, and / or methyl curdle, which are cashew oil extracts, as raw materials.

[0055] In one embodiment of the present invention, when the rubber composition contains the compound (1) and the oligomer (B), the content of the compound (1) relative to the total amount of the compound (1) and the oligomer (B) (hereinafter also referred to as "monomer ratio") is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, particularly preferably 85% or more, and preferably 100% or less. When the content of the oligomer (B) is the above-mentioned lower limit or more, the wear resistance of the vulcanized rubber composition can be improved without significantly impairing the fuel economy of the vulcanized rubber composition. The monomer percentage can be determined by calculating the RI surface percentage of the compound (1) and the RI surface percentage of the oligomer (B) by GPC analysis. Monomer percentage = RI surface percentage of compound (1) / (RI surface percentage of compound (1) + RI surface percentage of oligomer (B)) x 100 It can be calculated by:

[0056] <Method for producing compound (1)> The method for producing compound (1) is not particularly limited, and for example, compound (1) can be obtained by reacting cardanol with phosphorus trihalide, but since compound (1) and oligomer (B) can be produced in a single reaction, it is preferable to produce compound (1) by the following method. An example of the method for producing compound (1) and oligomer (B) is described below.

[0057] As a method for producing the compound (1) and the oligomer (B), a method of reacting cashew oil with phosphorus trihalide can be mentioned. Cashew oil contains cardanol, as well as cardol and / or methyl cardol. By using cashew oil containing cardol and / or methyl cardol in addition to cardanol as a raw material, the oligomer (B) can be produced in addition to the compound (1). Therefore, in the production of the compound (1), the compound (1) and the oligomer (B) may be separated from the mixture obtained by the reaction of the cashew oil with the phosphorus trihalide by a conventional method, for example, a separation means such as column chromatography, and the compound (1) and the oligomer (B) may be obtained and used separately, or a mixture of the compound (1) and the oligomer (B) adjusted to a desired monomer ratio may be used. The monomer ratio, which is the content of compound (1) in the mixture of compound (1) and oligomer (B), can also be adjusted by the contents of cardanol, cardulle and methyl cardulle that may be contained in cashew oil, and the contents of cardanol, cardulle and methyl cardulle can be adjusted by a conventional method, for example, a separation means such as column chromatography.

[0058] The contents of cardanol, cardulle and methyl cardulle that can be contained in the cashew oil can be appropriately selected depending on the desired monomer ratio and the number average molecular weight of the oligomer (B).

[0059] In one embodiment of the present invention, the content of cardanol contained in the cashew oil may be preferably 50% or more, more preferably 70% or more, even more preferably 80% or more, particularly preferably 90% or more, and may be preferably 99% or less, more preferably 98.5% or less, even more preferably 98% or less. The higher the content of cardanol, the higher the monomer ratio in the mixture of compound (1) and oligomer (B) may be.

[0060] In one embodiment of the present invention, the total content of curdle and methyl curdle contained in cashew oil is preferably 1% or more, more preferably 1.5% or more, even more preferably 2% or more, and is preferably 50% or less, more preferably 30% or less, even more preferably 20% or less, and particularly preferably 10% or less. The higher the total content of curdle and methyl curdle, the higher the content of oligomer (B) in the mixture of compound (1) and oligomer (B) can be.

[0061] The contents of cardanol, curd and methyl curd contained in cashew oil can be calculated by determining the area ratio of each peak of cardanol, curd and methyl curd by liquid chromatography analysis.

[0062] Examples of phosphorus trihalides include phosphorus trichloride, phosphorus tribromide, etc. Among the phosphorus trihalides, phosphorus trichloride is preferred from the viewpoint of easiness in improving the yield and from the viewpoint of economical production on an industrial scale.

[0063] In one embodiment of the present invention, when reacting cashew oil with phosphorus trihalide, it is preferable to use a catalyst from the viewpoint of facilitating the reaction. Examples of the catalyst include dehydrohalogenation agents such as amines, pyridines, pyrrolidines, and amides, and hydroxides of alkali metals or alkaline earth metals. These may be used alone or in combination of two or more kinds, for example, one type of dehydrohalogenation agent or hydroxide of alkali metals or alkaline earth metals may be used, or two or more kinds of these may be used in combination.

[0064] As the amines, any of primary amines, secondary amines, and tertiary amines may be used. As the amines, for example, t-butylamine, t-pentylamine, t-hexylamine, t-octylamine, di-t-butylamine, di-t-pentylamine, di-t-hexylamine, di-t-octylamine, trimethylamine, triethylamine, N,N-diisopropylethylamine, N,N-dimethylaniline, and N,N-diethylaniline are listed. As the amines, triethylamine is preferably used from the viewpoint of facilitating the reaction. As the pyridines, for example, pyridine and picoline are listed, and pyridine is preferably used. As the pyrrolidines, for example, 1-methyl-2-pyrrolidine is listed. As the amides, for example, N,N-dimethylformamide and N,N-dimethylacetamide are listed, and N,N-dimethylformamide is preferably used.

[0065] Examples of the hydroxide of an alkali metal or an alkaline earth metal include sodium hydroxide and calcium hydroxide, with sodium hydroxide being preferred.

[0066] The reaction is usually carried out in an organic solvent. The organic solvent is not particularly limited as long as it does not inhibit the reaction, and examples thereof include aromatic hydrocarbons, aliphatic hydrocarbons, oxygen-containing hydrocarbons, and halogenated hydrocarbons. The reaction may be carried out in one type of organic solvent, in a mixed solvent of two or more types of organic solvents, or in a mixed solvent of the organic solvent and another solvent.

[0067] Examples of aromatic hydrocarbons include benzene, toluene, xylene, and ethylbenzene. Examples of aliphatic hydrocarbons include n-hexane, n-heptane, and n-octane. Examples of oxygen-containing hydrocarbons include diethyl ether, dibutyl ether, tetrahydrofuran, and 1,4-dioxane. Examples of halogenated hydrocarbons include chloroform, carbon tetrachloride, monochlorobenzene, dichloromethane, 1,2-dichloroethane, and dichlorobenzene. Among these organic solvents, it is preferable to use toluene, xylene, n-hexane, n-heptane, diethyl ether, tetrahydrofuran, 1,4-dioxane, chloroform or dichloromethane from the viewpoint of improving the yield.

[0068] In the production of compound (1), the amounts of cashew oil, phosphorus trihalide and amines used can be appropriately selected depending on the desired monomer ratio and number average molecular weight of oligomer (B).

[0069] In one embodiment of the present invention, the amount of phosphorus trihalide used is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and preferably 40 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, per 100 parts by mass of cashew oil.

[0070] In one embodiment of the present invention, the amount of the catalyst such as amines used is preferably 0.5 mol or more, more preferably 1 mol or more, and even more preferably 3 mol or more, and is preferably 10 mol or less, more preferably 7 mol or less, and even more preferably 5 mol or less, relative to 1 mol of phosphorus trichloride. When the amount of the amines used is within the above range, the reaction is easily promoted.

[0071] The method for reacting cashew oil with phosphorus trihalide is not particularly limited, but from the viewpoint of easy control of reaction heat, it is preferable to carry out the reaction by a method in which phosphorus trihalide is added dropwise or the like to a mixture containing cashew oil and a catalyst, or a method in which cashew oil is added dropwise or the like to a mixture containing phosphorus trihalide and a catalyst.

[0072] The reaction temperature between cashew oil and phosphorus trihalide is not particularly limited, and may be, for example, 60 to 200°C, preferably 100 to 130°C, and the reaction time is also not particularly limited, and may be, for example, about 30 minutes to 12 hours. The reaction may be carried out in air or in an inert gas atmosphere such as nitrogen gas or argon gas, but from the viewpoint of easily suppressing hydrolysis of phosphorus trihalide, it is preferable to carry out the reaction in an inert gas atmosphere. The reaction may be carried out under normal pressure, under pressure, or under reduced pressure.

[0073] Compound (1) and oligomer (B) can be isolated by separation and purification using a conventional method, for example, a separation means such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, or a combination of these.

[0074] <Amine compound (A)> The rubber composition of the present invention preferably further contains an amine compound (A) having a hydroxyalkyl group. When the rubber composition of the present invention further contains the amine compound (A), the abrasion resistance of the vulcanized rubber composition can be improved without significantly impairing the fuel economy due to the interaction with silica and the like. The content of the amine compound (A) is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 8 parts by mass, even more preferably 0.01 to 6 parts by mass, even more preferably 0.05 to 5 parts by mass, and particularly preferably 0.07 to 4 parts by mass, relative to 100 parts by mass of the compound (1). When the content of the amine compound (A) is within the above range, the abrasion resistance of the vulcanized rubber composition can be improved without significantly impairing the fuel economy.

[0075] The content of the amine compound (A) in the rubber composition of the present invention relative to 100 parts by mass of the compound (1) may be calculated using an analytical device such as liquid chromatography, or may be calculated from the charge ratio when preparing the rubber composition.

[0076] The rubber composition of the present invention preferably contains an amine compound (A) having at least one kind of hydroxyalkyl group. As the amine compound (A), one kind of amine compound having a hydroxyalkyl group may be used, or two or more kinds of amine compounds having a hydroxyalkyl group may be used. In this specification, the amine compound (A) is a compound having at least one nitrogen atom and at least one linear or branched alkyl group having at least one hydroxyl group, and may be a monoamine compound, a diamine compound, a triamine compound, or a tetraamine compound, but is preferably a monoamine compound or a diamine compound, and more preferably a monoamine compound. The amine compound (A) is preferably (A1) a compound in which one or two of three hydrogen atoms of ammonia are substituted with a hydroxyalkyl group, and the remaining hydrogen atoms are not substituted or are substituted with a substituent such as an aliphatic group or an aromatic group, (A2) a compound in which all three hydrogen atoms of ammonia are substituted with a hydroxyalkyl group, (A3) a compound in which two nitrogen atoms are linked with an alkylene group (preferably an alkylene group having 1 to 4 carbon atoms), one, two or three of four hydrogen atoms bonded to the nitrogen atoms are substituted with a hydroxyalkyl group, and the remaining hydrogen atoms are not substituted or are substituted with a substituent such as an aliphatic group or an aromatic group, (A4) a compound in which two nitrogen atoms are linked with an alkylene group (preferably an alkylene group having 1 to 4 carbon atoms), and all four hydrogen atoms bonded to the nitrogen atoms are substituted with a hydroxyalkyl group. More preferably, the amine compound (A) is an alkanolamine. An alkanolamine is a saturated aliphatic amine having a hydroxyl group in the molecule. Furthermore, the amine compound (A) may be a primary amine compound, a secondary amine, or a tertiary amine, but is preferably a tertiary amine compound.

[0077] In one preferred embodiment of the present invention, the amine compound (A) is preferably an alkanolamine, more preferably a compound represented by the formula (I): [ka] [In formula (I), Y 1 , Y 2 and Y 3 each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms and at least one hydroxyl group, provided that Y 1 ~Y 3 at least one of represents an alkyl group having 1 to 8 carbon atoms and having at least one hydroxyl group. Or formula (II): [ka] [In formula (II), Y 4 , Y 5 , Y 6 and Y 7 each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms and at least one hydroxyl group, provided that Y 4 ~Y 7 at least one of represents an alkyl group having 1 to 8 carbon atoms and having at least one hydroxyl group, and B represents an alkylene group having 1 to 4 carbon atoms. When the alkanolamine is an alkanolamine represented by formula (I) or formula (II), the abrasion resistance of the vulcanized rubber composition can be improved without significantly impairing the fuel economy of the composition.

[0078] In formula (I) or (II), examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, a t-pentyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 2-ethylpropyl group, an n-hexyl group, an n-heptyl group, an isoheptyl group, an n-octyl group, an isooctyl group, and a 2-ethylhexyl group. The number of carbon atoms in the alkyl group is preferably 1 to 6, and more preferably 1 to 4.

[0079] Examples of the alkyl group having 1 to 8 carbon atoms and at least one hydroxyl group include the alkyl groups exemplified above in which at least one hydrogen atom has been substituted with a hydroxyl group. Specific examples include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, and a hydroxybutyl group. The number of hydroxyl groups in the alkyl group having 1 to 8 carbon atoms and at least one hydroxyl group is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1.

[0080] Examples of the alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, and an isobutylene group. The alkylene group having 1 to 4 carbon atoms is preferably a linear alkylene group having 1 to 4 carbon atoms, more preferably a methylene group, an ethylene group, or an n-propylene group, even more preferably a methylene group or an ethylene group, and even more preferably an ethylene group. The number of carbon atoms in the alkylene group is preferably 1 to 3, more preferably 1 or 2, and even more preferably 2.

[0081] Specific examples of the compound represented by formula (I) include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, tributanolamine, tripentanolamine, methylethanolamine, methylisopropanolamine, methyldiethanolamine, methyldiisopropanolamine, diethanolisopropanolamine, diisopropanolethanolamine, and tris(2-hydroxybutyl)amine.

[0082] Specific examples of the compound represented by formula (II) include tetrahydroxyethylethylenediamine, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, and the like.

[0083] In one embodiment of the present invention, Y in formula (I) 1 , Y 2 and Y 3And Y in formula (II) 4 , Y 5 , Y 6 and Y 7 are preferably each independently -CH-CH(OH)-R 6 [In the formula, R 6 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0084] In one embodiment of the present invention, the alkanolamine is preferably an alkanolamine of formula (I).

[0085] <Rubber component> Examples of rubber components include styrene-butadiene copolymer rubber (SBR), natural rubber (NR) (including modified natural rubber, such as epoxidized natural rubber and deproteinized natural rubber), polybutadiene rubber (BR), polyisoprene rubber (IR), nitrile rubber (NBR), chloroprene rubber (CR), isoprene-isobutylene copolymer rubber (IIR), ethylene-propylene-diene copolymer rubber (EPDM), halogenated butyl rubber (HR), etc. Only one type of rubber component may be used, or two or more types may be used in combination.

[0086] Examples of SBR include emulsion-polymerized SBR and solution-polymerized SBR described on pages 210 to 211 of "Rubber Industry Handbook, Fourth Edition" compiled by the Japan Rubber Association. Emulsion-polymerized SBR and solution-polymerized SBR may be used in combination.

[0087] The solution-polymerized SBR includes modified solution-polymerized SBR obtained by modification with a modifying agent and having at least one element of nitrogen, tin, and silicon at the molecular end. Examples of the modifying agent include lactam compounds, amide compounds, urea compounds, N,N-dialkylacrylamide compounds, isocyanate compounds, imide compounds, silane compounds having an alkoxy group, aminosilane compounds, combined modifiers of tin compounds and silane compounds having an alkoxy group, combined modifiers of alkylacrylamide compounds and silane compounds having an alkoxy group, etc. These modifiers may be used alone or in combination. Specific examples of modified solution-polymerized SBR include solution-polymerized SBR modified at the molecular end with 4,4'-bis(dialkylamino)benzophenone such as "Nipol (registered trademark) NS116" manufactured by Nippon Zeon Co., Ltd., solution-polymerized SBR modified at the molecular end with a halide tin compound such as "SL574" manufactured by JSR Corporation, and silane-modified solution-polymerized SBR such as "E10" and "E15" manufactured by Asahi Kasei Corporation.

[0088] Furthermore, oil-extended SBR, which is obtained by adding oil such as process oil or aromatic oil to emulsion-polymerized SBR or solution-polymerized SBR, can also be used.

[0089] Examples of natural rubber include natural rubbers of grades such as RSS#1, RSS#3, TSR20, and SIR20. Examples of epoxidized natural rubber include those with an epoxidation degree of 10 to 60 mol% (for example, ENR25 and ENR50 manufactured by Kunpuran Guthrie). Deproteinized natural rubber having a total nitrogen content of 0.3 mass% or less is preferable. Other modified natural rubbers include modified natural rubbers containing polar groups obtained by reacting natural rubber with 4-vinylpyridine, N,N-dialkylaminoethyl acrylate (for example, N,N-diethylaminoethyl acrylate), 2-hydroxyacrylate, etc.

[0090] The BR may be any BR commonly used in the tire industry, which is often used in blends with SBR and / or natural rubber.

[0091] As the BR, a BR having a high cis content is preferred because it has a high effect of improving abrasion resistance, and a high-cis BR having a cis content of 95% by mass or more is more preferred. Examples of high-cis BR include BR1220 manufactured by Zeon Corporation and BR150B manufactured by Ube Industries, Ltd.

[0092] Modified BR obtained by modification with a modifying agent and having at least one element of nitrogen, tin, and silicon at the molecular end can also be used. Examples of the modifying agent include 4,4'-bis(dialkylamino)benzophenone, halogenated tin compounds, lactam compounds, amide compounds, urea compounds, N,N-dialkylacrylamide compounds, isocyanate compounds, imide compounds, silane compounds having an alkoxy group (e.g., trialkoxysilane compounds), aminosilane compounds, tin compounds, and alkylacrylamide compounds. These modifying agents may be used alone or in combination. Examples of the modified BR include tin-modified BR such as "Nipol (registered trademark) BR 1250H" manufactured by Zeon Corporation.

[0093] The rubber component preferably contains a diene rubber. Here, the diene rubber means a rubber made from a diene monomer having a conjugated double bond. Examples of the diene rubber include styrene-butadiene copolymer rubber (SBR), natural rubber (NR), polybutadiene rubber (BR), polyisoprene rubber (IR), nitrile rubber (NBR), and chloroprene rubber (CR).

[0094] When a diene rubber is used, the amount of the diene rubber in the rubber component (i.e., the amount of the diene rubber per 100% by mass of the rubber component) is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, further preferably 80 to 100% by mass, and most preferably 100% by mass. That is, it is most preferable that the rubber component is made of a diene rubber.

[0095] In one embodiment of the present invention, the rubber component preferably contains SBR. In this embodiment, the amount of SBR in the rubber component is preferably 50 to 100 mass%, more preferably 70 to 100 mass%, further preferably 80 to 100 mass%, and most preferably 100 mass%. That is, in this embodiment, it is most preferable that the rubber component consists of SBR.

[0096] In one embodiment of the present invention, the rubber component preferably contains SBR and BR. In this embodiment, the total amount of SBR and BR in the rubber component is preferably 50 to 100 mass%, more preferably 70 to 100 mass%, even more preferably 80 to 100 mass%, and most preferably 100 mass%. That is, in this embodiment, it is most preferable that the rubber component consists of SBR and BR. In this embodiment, the mass ratio of the amount of BR to the amount of SBR (amount of BR / amount of SBR) is preferably 5 / 95 to 50 / 50, more preferably 10 / 90 to 40 / 60, and even more preferably 20 / 80 to 40 / 60, from the viewpoints of fuel economy and wear resistance.

[0097] <Vulcanization accelerator> As the vulcanization accelerator, for example, those described in the Rubber Industry Handbook, Fourth Edition (published by the Japan Rubber Association on January 20, 1994) can be used. Only one type of vulcanization accelerator may be used, or two or more types may be used. As the vulcanization accelerator, for example, sulfenamide-based vulcanization accelerators, thiazole-based vulcanization accelerators, guanidine-based vulcanization accelerators, etc. can be mentioned.

[0098] Examples of sulfenamide vulcanization accelerators include N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS), N-oxydiethylene-2-benzothiazolylsulfenamide (OBS), N,N-dicyclohexyl-2-benzothiazolylsulfenamide (DCBS), etc. The sulfenamide vulcanization accelerator may be used alone or in combination of two or more kinds.

[0099] Examples of the thiazole vulcanization accelerator include 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), 2-mercaptobenzothiazole cyclohexylamine salt (CMBT), 2-mercaptobenzothiazole zinc salt (ZMBT), etc. The thiazole vulcanization accelerator may be used alone or in combination of two or more kinds.

[0100] Examples of the guanidine vulcanization accelerator include diphenyl guanidine (DPG), N,N'-di-o-tolyl guanidine (DOTG), etc. The guanidine vulcanization accelerator may be used alone or in combination of two or more kinds.

[0101] The amount of the vulcanization accelerator (when two or more kinds of vulcanization accelerators are used, the total amount) is preferably 0.5 to 10.5 parts by mass, more preferably 0.7 to 8 parts by mass, further preferably 0.8 to 6 parts by mass, and particularly preferably 0.8 to 5.5 parts by mass, per 100 parts by mass of the rubber component.

[0102] The vulcanization accelerator preferably includes a sulfenamide-based vulcanization accelerator, which is preferably at least one selected from the group consisting of N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS), N-oxydiethylene-2-benzothiazolylsulfenamide (OBS), and N,N-dicyclohexyl-2-benzothiazolylsulfenamide (DCBS), and more preferably N-cyclohexyl-2-benzothiazolylsulfenamide (CBS).

[0103] When a sulfenamide vulcanization accelerator is used, the amount thereof (when two or more kinds of sulfenamide vulcanization accelerators are used, the total amount thereof) is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 7 parts by mass, further preferably 0.1 to 5 parts by mass, and particularly preferably 1 to 5 parts by mass, per 100 parts by mass of the rubber component.

[0104] The mass ratio of the amount of the sulfur component to the amount of the vulcanization accelerator (amount of sulfur component / amount of vulcanization accelerator) is not particularly limited, but is preferably 1 / 10 to 10 / 1, more preferably 1 / 5 to 5 / 1. When two or more types of vulcanization accelerators (e.g., CBS and DPG) are used, the mass ratio is calculated using the amount of the sulfur component and the total amount of the two or more types of vulcanization accelerators.

[0105] <Filling agent> One of the features of the present invention is the use of silica as a filler. The BET specific surface area of ​​the silica is preferably 20 to 400 m 2 / g, more preferably 20 to 350m 2 / g, more preferably 20 to 300m 2 / g. This BET specific surface area can be measured by a multipoint nitrogen adsorption method (BET method).

[0106] Examples of silica include (i) silica having a pH of 6 to 8, (ii) silica containing 0.2 to 1.5 mass % sodium, (iii) spherical silica having a circularity of 1 to 1.3, (iv) silica surface-treated with silicone oil (e.g., dimethyl silicone oil), organosilicon compounds containing ethoxysilyl groups, alcohols (e.g., ethanol, polyethylene glycol), etc., and (v) a mixture of two or more types of silica having different surface areas. These may be used alone or in combination of two or more types.

[0107] Examples of commercially available silica products include "Nipsil (registered trademark) AQ" and "Nipsil (registered trademark) AQ-N" manufactured by Tosoh Silica Corporation, "Ultrasil (registered trademark) VN3", "Ultrasil (registered trademark) VN3-G", "Ultrasil (registered trademark) 360", "Ultrasil (registered trademark) 7000", and "Ultrasil (registered trademark) 9100GR" manufactured by EVONIK, and "Zeosil (registered trademark) 115GR", "Zeosil (registered trademark) 1115MP", "Zeosil (registered trademark) 1205MP", and "Zeosil (registered trademark) Z85MP" manufactured by Solvay.

[0108] From the viewpoints of fuel economy and abrasion resistance, the amount of silica is preferably 10 to 120 parts by mass, more preferably 20 to 120 parts by mass, even more preferably 30 to 120 parts by mass, particularly preferably 40 to 100 parts by mass, and most preferably 50 to 100 parts by mass, per 100 parts by mass of the rubber component.

[0109] In the present invention, carbon black may be used as a filler. The BET specific surface area of ​​the carbon black is preferably 10 to 130 m 2 / g, more preferably 20 to 130m 2 / g, more preferably 40 to 130m 2 / g. This BET specific surface area can be measured by a multipoint nitrogen adsorption method (BET method).

[0110] Examples of carbon black include those described on page 494 of "Rubber Industry Handbook, Fourth Edition" edited by the Japan Rubber Association. Only one type of carbon black may be used, or two or more types may be used in combination. Preferred carbon blacks are HAF (High Abrasion Furnace), SAF (Super Abrasion Furnace), ISAF (Intermediate SAF), ISAF-HM (Intermediate SAF-High Modulus), FEF (Fast Extrusion Furnace), MAF (Medium Abrasion Furnace), GPF (General Purpose Furnace), and SRF (Semi-Reinforcing Furnace).

[0111] When carbon black is used, the amount thereof is preferably 1 to 40 parts by mass, more preferably 1 to 30 parts by mass, and further preferably 1 to 25 parts by mass, per 100 parts by mass of the rubber component, from the viewpoints of fuel economy, abrasion resistance, and reinforcing property.

[0112] When carbon black is used, the mass ratio of the amount of carbon black to the amount of silica (amount of carbon black / amount of silica) is preferably 1 / 120 to 3 / 4, more preferably 1 / 100 to 1 / 2, and even more preferably 1 / 100 to 5 / 12, from the viewpoints of fuel economy and abrasion resistance.

[0113] In the present invention, fillers other than silica and carbon black may be used, such as aluminum hydroxide, ground bituminous coal, talc, clay (especially calcined clay), and titanium oxide.

[0114] Aluminum hydroxide has a nitrogen adsorption specific surface area of ​​5 to 250 m 2 / g and DOP supply amount of 50 to 100 ml / 100 g are exemplified.

[0115] The average particle size of the pulverized bituminous coal is preferably 0.001 mm or more, and preferably 0.1 mm or less, more preferably 0.05 mm or less, and further preferably 0.01 mm or less. The average particle size of the pulverized bituminous coal is the average particle size on a mass basis calculated from the particle size distribution measured in accordance with JIS Z 8815-1994.

[0116] The specific gravity of the pulverized bituminous coal is preferably 1.6 or less, more preferably 1.5 or less, and even more preferably 1.3 or less. The specific gravity of the pulverized bituminous coal is preferably 0.5 or more, and more preferably 1.0 or more. When the specific gravity of the pulverized bituminous coal is equal to or more than the lower limit and equal to or less than the upper limit, the fuel economy of the tire is likely to be improved, and the processability during kneading can be good.

[0117] <Sulfur component> Examples of the sulfur component include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur.

[0118] The amount of the sulfur component is preferably 0.1 to 5 parts by mass, more preferably 0.1 to 4 parts by mass, and further preferably 0.1 to 3 parts by mass, per 100 parts by mass of the rubber component.

[0119] <Other ingredients> In the present invention, other components different from the above-mentioned compound (1), rubber component, vulcanization accelerator, filler, and sulfur component may be used. As the other components, those known in the rubber field may be used, for example, compounds that can be bonded with silica (e.g., silane coupling agents), vulcanization accelerator assistants, resins, viscoelasticity improvers, antioxidants, processing assistants, oils, waxes, peptizers, retarders, compounds having oxyethylene units, and catalysts (cobalt naphthenate, etc.). As for the other components, only one kind may be used, or two or more kinds may be used in combination.

[0120] Examples of compounds that can be bonded to silica include bis(3-triethoxysilylpropyl) tetrasulfide (e.g., EVONIK's "Si-69"), bis(3-triethoxysilylpropyl) disulfide (e.g., EVONIK's "Si-75"), bis(3-diethoxymethylsilylpropyl) tetrasulfide, bis(3-diethoxymethylsilylpropyl) disulfide, 3-octanoylthiopropyl triethoxysilane (also known as "Octanethioic acid S-[3-(triethoxysilyl)propyl] esters, e.g., "NXT Silane" manufactured by General Electronic Silicones), octanethioic acid S-[3-{(2-methyl-1,3-propanedialkoxy)ethoxysilyl}propyl] ester, octanethioic acid S-[3-{(2-methyl-1,3-propanedialkoxy)methylsilyl}propyl] ester, methyltrimethoxysilane, methyltriethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isobutyl Trimethoxysilane, isobutyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(methoxyethoxy)silane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane , N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane and 3-isocyanatopropyltriethoxysilane.Among these, bis(3-triethoxysilylpropyl)tetrasulfide (e.g., "Si-69" manufactured by EVONIK), bis(3-triethoxysilylpropyl)disulfide (e.g., "Si-75" manufactured by EVONIK), and 3-octanoylthiopropyltriethoxysilane (e.g., "NXT Silane" manufactured by General Electronic Silicones) are preferred.

[0121] When a compound capable of bonding with silica is used, the amount thereof is preferably 2 to 10 parts by mass per 100 parts by mass of silica.

[0122] In addition to compounds capable of bonding with silica, monohydric alcohols such as ethanol, butanol, and octanol; polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, pentaerythritol, and polyether polyols; N-alkylamines; amino acids; and liquid polybutadiene whose molecular terminals are carboxy- or amine-modified may be used.

[0123] Examples of the vulcanization accelerator include zinc oxide, a citraconimide compound, an alkylphenol-sulfur chloride condensate, an organic thiosulfate compound, and a compound represented by the formula (III): R 16 -SSR 17 -SSR 18 (III) [In the formula, R 17 is C 2-10 R represents an alkanediyl group. 16 and R 18 each independently represents a monovalent organic group containing a nitrogen atom. Examples of the compound include those represented by the following formula: In the present invention, zinc oxide is included in the concept of the vulcanization accelerator, but is not included in the concept of the above-mentioned filler.

[0124] When zinc oxide is used, the amount thereof is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and further preferably 0.1 to 10 parts by mass, per 100 parts by mass of the rubber component.

[0125] As the citraconic imide compound, biscitraconimide is preferable because it is thermally stable and has excellent dispersibility in the rubber component.Specific examples thereof include 1,2-biscitraconimide methylbenzene, 1,3-biscitraconimide methylbenzene, 1,4-biscitraconimide methylbenzene, 1,6-biscitraconimide methylbenzene, 2,3-biscitraconimide methyltoluene, 2,4-biscitraconimide methyltoluene, 2,5-biscitraconimide methyltoluene, 2,6-biscitraconimide methyltoluene, 1,2-biscitraconimide ethylbenzene, 1,3-biscitraconimide ethylbenzene, 1,4-biscitraconimide ethylbenzene, 1,6-biscitraconimide ethylbenzene, 2,3-biscitraconimide ethyltoluene, 2,4-biscitraconimide ethyltoluene, 2,5-biscitraconimide ethyltoluene, and 2,6-biscitraconimide ethyltoluene.

[0126] Among the citraconic imide compounds, 1,3-biscitraconimidomethylbenzene represented by the following formula is preferred because it is particularly thermally stable, has particularly excellent dispersibility in the rubber component, and can produce a vulcanized rubber composition with high hardness (Hs) (reversion control). [ka]

[0127] As a vulcanization accelerating aid, a vulcanized rubber composition having a high hardness (Hs) can be obtained by using a compound represented by the formula (IV): [ka] [In the formula, n is an integer of 0 to 10, X is an integer of 2 to 4, and R 19 is C 5-12is an alkyl group. It is preferable to use an alkylphenol-sulfur chloride condensate represented by the following formula:

[0128] In order to improve the dispersibility of the alkylphenol-sulfur chloride condensate (IV) in the rubber component, n in the formula (IV) is preferably an integer of 1 to 9.

[0129] When X is 2 to 4, the alkylphenol-sulfur chloride condensate (IV) tends to be thermally stable, and the sulfur content (sulfur mass) in the alkylphenol-sulfur chloride condensate (IV) is appropriate. X is preferably 2 because high hardness can be efficiently expressed (reversion suppression).

[0130] R 19 is C 5-12 It is an alkyl group. Because of the good dispersibility of the alkylphenol-sulfur chloride condensate (IV) in the rubber component, R 19 is preferably C 6-9 It is an alkyl group.

[0131] Specific examples of the alkylphenol-sulfur chloride condensate (IV) include those in which n in formula (IV) is 0 to 10, X is 2, and R 19 is an octyl group, and the sulfur content is 24 mass %.

[0132] As a vulcanization accelerating aid, a vulcanized rubber composition having a high hardness (Hs) can be obtained (reversion suppression), and therefore, the compound represented by the formula (V): HO3S-S-(CH2) s -S-SO3H(V) [In the formula, s is an integer of 3 to 10.] It is preferable to use a salt of an organic thiosulfate compound represented by the formula (hereinafter sometimes referred to as "organic thiosulfate compound salt (V)"). An organic thiosulfate compound salt (V) containing water of crystallization may be used. Examples of the organic thiosulfate compound salt (V) include lithium salt, potassium salt, sodium salt, magnesium salt, calcium salt, barium salt, zinc salt, nickel salt, cobalt salt, etc., and potassium salt and sodium salt are preferable.

[0133] s is an integer of 3 to 10, and preferably an integer of 3 to 6. When s is 2 or less, sufficient thermal fatigue resistance tends not to be obtained, and when s is 11 or more, the effect of improving thermal fatigue resistance by the organic thiosulfate compound salt (V) may not be sufficiently obtained.

[0134] As the organic thiosulfate compound salt (V), from the viewpoint of stability at room temperature and normal pressure, the sodium salt monohydrate and the sodium salt dihydrate are preferred, and from the viewpoint of cost, the organic thiosulfate compound salt (V) obtained from sodium thiosulfate is more preferred, and sodium 1,6-hexamethylenedithiosulfate dihydrate represented by the following formula is even more preferred. [ka]

[0135] It disperses well in rubber components, and when used in combination with alkylphenol-sulfur chloride condensate (IV), it increases the -S of alkylphenol-sulfur chloride condensate (IV). X -bridge to form a hybrid bridge with the alkylphenol-sulfur chloride condensate (IV), R 16 -SSR 17 -SSR 18 (III) [In the formula, R 17 is C 2-10 R represents an alkanediyl group. 16 and R 18each independently represents a monovalent organic group containing a nitrogen atom. It is preferable to use a compound represented by the following formula as a vulcanization accelerating aid.

[0136] R 17 is C 2-10 Alkanediyl groups, preferably C 4-8 An alkanediyl group is preferably a linear C 4-8 R is an alkanediyl group. 17 R is preferably linear. 17 If the carbon number of R is 1 or less, the thermal stability may be poor. 17 If the number of carbon atoms is 11 or more, the distance between the polymers via the vulcanization accelerating aid becomes long, and the effect of adding the vulcanization accelerating aid may not be obtained.

[0137] R 16 and R 18 are each independently a monovalent organic group containing a nitrogen atom. The monovalent organic group containing a nitrogen atom is preferably one containing at least one aromatic ring, and more preferably one containing an aromatic ring and a =NC(=S)- group. 16 and R 18 may be the same or different, but is preferably the same for reasons such as ease of production.

[0138] Examples of the compound (III) include 1,2-bis(dibenzylthiocarbamoyldithio)ethane, 1,3-bis(dibenzylthiocarbamoyldithio)propane, 1,4-bis(dibenzylthiocarbamoyldithio)butane, 1,5-bis(dibenzylthiocarbamoyldithio)pentane, 1,6-bis(dibenzylthiocarbamoyldithio)hexane, 1,7-bis(dibenzylthiocarbamoyldithio)heptane, 1,8-bis(dibenzylthiocarbamoyldithio)octane, 1,9-bis(dibenzylthiocarbamoyldithio)nonane, and 1,10-bis(dibenzylthiocarbamoyldithio)decane. Among these, 1,6-bis(dibenzylthiocarbamoyldithio)hexane is preferred because it is thermally stable and has excellent dispersibility in the rubber component.

[0139] Commercially available products of compound (III) include, for example, VULCUREN TRIAL PRODUCT KA9188 and VULCUREN VP KA9188 (1,6-bis(dibenzylthiocarbamoyldithio)hexane) manufactured by Bayer AG.

[0140] In the present invention, organic compounds such as resorcinol, resorcinol resins, modified resorcinol resins, cresol resins, modified cresol resins, phenol resins, modified phenol resins, and other resins may be used. By using resorcinol or these resins, the elongation at break and the complex modulus of elasticity of the vulcanized rubber composition can be improved. In addition, when the rubber composition is used to manufacture a rubber product that comes into contact with a cord, the use of resorcinol or resins can improve adhesion to the cord.

[0141] Resorcinol includes, for example, resorcinol manufactured by Sumitomo Chemical Co., Ltd. Resorcinol resin includes, for example, resorcinol-formaldehyde condensate Modified resorcinol resin includes, for example, resorcinol resin with some of the repeating units alkylated Specifically, Penacolite resin B-18-S and B-20 manufactured by Indospec, Sumikanol 620 manufactured by Taoka Chemical Co., Ltd, R-6 manufactured by Uniroyal, SRF1501 manufactured by Schenectady Chemical Co., and Arofene 7209 manufactured by Ashland Corporation are listed.

[0142] An example of a cresol resin is a cresol-formaldehyde condensate. An example of a modified cresol resin is a cresol resin in which the terminal methyl group is replaced with a hydroxyl group, or a cresol resin in which some of the repeating units are alkylated. Specific examples include Sumikanol 610 manufactured by Taoka Chemical Co., Ltd. and PR-X11061 manufactured by Sumitomo Bakelite Co., Ltd.

[0143] Examples of phenolic resins include phenol-formaldehyde condensates, and examples of modified phenolic resins include resins modified with cashew oil, tall oil, linseed oil, various animal and vegetable oils, unsaturated fatty acids, rosin, alkylbenzene resins, aniline, melamine, etc.

[0144] Other resins include, for example, methoxylated methylol melamine resins such as "Sumikanol 507AP" manufactured by Sumitomo Chemical Co., Ltd.; coumarone-indene resins such as Coumarone Resin NG4 (softening point 81 to 100°C) manufactured by Nippon Steel Chemical Co., Ltd. and "Process Resin AC5" (softening point 75°C) manufactured by Kobe Oil Chemical Industry Co., Ltd.; terpene resins such as terpene resins, terpene-phenol resins, and aromatic modified terpene resins; rosin derivatives such as "Nikanol (registered trademark) A70" (softening point 70 to 90°C) manufactured by Mitsubishi Gas Chemical Co., Ltd.; hydrogenated rosin derivatives; novolac-type alkylphenol resins; resol-type alkylphenol resins; C5-based petroleum resins; and liquid polybutadiene.

[0145] Examples of the viscoelasticity improver include N,N'-bis(2-methyl-2-nitropropyl)-1,6-hexanediamine (e.g., "Sumifine (registered trademark) 1162" manufactured by Sumitomo Chemical Co., Ltd.), dithiouracil compounds described in JP-A-63-23942, "Tackirol (registered trademark) AP" and "Tackirol (registered trademark) V-200" manufactured by Taoka Chemical Co., Ltd., alkylphenol-sulfur chloride condensates described in JP-A-2009-138148, 1,6-bis(dibenzylthiocarbamoyldithio)hexane (e.g., Bayer Chemical Co., Ltd.), and the like. "KA9188" manufactured by Flexis), 1,6-hexamethylene dithiosulfate disodium salt dihydrate, 1,3-bis(citraconimidomethyl)benzene (e.g., "Perkalink 900" manufactured by Flexis), 1-benzoyl-2-phenylhydrazide, 1-hydroxy-N'-(1-methylethylidene)-2-naphthoic acid hydrazide, 3-hydroxy-N'-(1-methylethylidene)-2-naphthoic acid hydrazide, 1-hydroxy-N'-(1-methylpropylidene) as described in JP-A-2004-91505, 1-Hydroxy-N'-(1-methylpropylidene)-2-naphthoic acid hydrazide, 3-hydroxy-N'-(1-methylpropylidene)-2-naphthoic acid hydrazide, 1-hydroxy-N'-(1,3-dimethylbutylidene)-2-naphthoic acid hydrazide, 3-hydroxy-N'-(1,3-dimethylbutylidene)-2-naphthoic acid hydrazide, 1-hydroxy-N'-(2-furylmethylene)-2-naphthoic acid hydrazide, 3-hydroxy-N'-(2-furylmethylene)-2-naphthoic acid hydrazide and other carboxylic acid hydrazide derivatives, JP 2000-190 704, 3-hydroxy-N'-(1,3-dimethylbutylidene)-2-naphthoic acid hydrazide, 3-hydroxy-N'-(1,3-diphenylethylidene)-2-naphthoic acid hydrazide, 3-hydroxy-N'-(1-methylethylidene)-2-naphthoic acid hydrazide, bismercaptooxadiazole compounds described in JP-A-2006-328310, pyrithione salt compounds described in JP-A-2009-40898, and cobalt hydroxide compounds described in JP-A-2006-249361.

[0146] Examples of the antiaging agent include those described on pages 436 to 443 of "Rubber Industry Handbook, Fourth Edition" edited by the Japan Rubber Association. As the antiaging agent, N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (abbreviated as "6PPD", for example, Kawaguchi Chemical's ANTEGE (registered trademark) 6C), reaction product of aniline and acetone (abbreviated as "TMDQ"), poly(2,2,4-trimethyl-1,2-)dihydroquinoline) (for example, Matsubara Sangyo Co., Ltd.'s "Antioxidant FR"), synthetic wax (paraffin wax, etc.), and vegetable wax are preferably used.

[0147] When an antioxidant is used, the amount thereof is preferably 0.01 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, and further preferably 0.1 to 5 parts by mass, per 100 parts by mass of the rubber component.

[0148] Examples of processing aids include fatty acids such as ricinoleic acid, palmitic acid, stearic acid, oleic acid, palmitic acid, and the like, esters and amides thereof, and fatty acid metal salts such as zinc stearate, barium stearate, calcium stearate, and zinc laurate. Examples of commercially available products include "STRUKTOL A50P", "STRUKTOL A60", "STRUKTOL EF44", "STRUKTOL HT204", "STRUKTOL HT207", "STRUKTOL HT254", "STRUKTOL HT266", and "STRUKTOL WB16" manufactured by SCHILL & SEILACHER Gmbh. & CO.

[0149] When a processing aid is used, the amount thereof is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and further preferably 0.1 to 10 parts by mass, per 100 parts by mass of the rubber component.

[0150] When stearic acid is used as a processing aid, the amount thereof is preferably 0.01 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, and further preferably 0.1 to 5 parts by mass, per 100 parts by mass of the rubber component.

[0151] Examples of the oil include process oil, vegetable oil, etc. Examples of the process oil include paraffin-based process oil, naphthene-based process oil, aromatic process oil, MES (light extract solvate) oil, and TDAE (treated distillate aromatic extract) oil. Examples of commercially available products include aromatic oil (Cosmo Oil's "NC-140"), process oil (Idemitsu Kosan's "Diana Process PS32"), and TDAE oil (H&R's "VivaTec500").

[0152] When the oil is used, the amount thereof is preferably from 5 to 70 parts by mass, and more preferably from 20 to 60 parts by mass, per 100 parts by mass of the rubber component.

[0153] Examples of the wax include "Sunnock (registered trademark) Wax" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. and "OZOACE-0355" manufactured by Nippon Seiro Co., Ltd.

[0154] The peptizing agent is not particularly limited as long as it is one that is commonly used in the rubber field, but examples thereof include aromatic mercaptan-based peptizing agents, aromatic disulfide-based peptizing agents, and aromatic mercaptan metal salt-based peptizing agents described on pages 446 to 449 of the "Rubber Industry Handbook, Fourth Edition" edited by the Japan Rubber Association. Among these, dixylyl disulfide and o,o'-dibenzamide diphenyl disulfide ("Noctizer SS" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) are preferred. Only one type of peptizing agent may be used, or two or more types may be used in combination.

[0155] When a peptizing agent is used, the amount thereof is preferably from 0.01 to 1 part by mass, and more preferably from 0.05 to 0.5 parts by mass, per 100 parts by mass of the rubber component.

[0156] Examples of retarders include phthalic anhydride, benzoic acid, salicylic acid, N-nitrosodiphenylamine, N-(cyclohexylthio)phthalimide (CTP), sulfonamide derivatives, diphenylurea, bis(tridecyl)pentaerythritol diphosphite, and the like, with N-(cyclohexylthio)phthalimide (CTP) being preferred.

[0157] When a retarder is used, the amount thereof is preferably from 0.01 to 1 part by mass, and more preferably from 0.05 to 0.5 parts by mass, per 100 parts by mass of the rubber component.

[0158] In the present invention, the formula: -O-(CH2-CH2-O) r -H [wherein r is an integer of 1 or more] may be used. In the above formula, r is preferably 2 or more, more preferably 3 or more. Also, r is preferably 16 or less, more preferably 14 or less. If r is 17 or more, compatibility with the rubber component and reinforcing properties tend to decrease.

[0159] The position of the oxyethylene unit in the compound having an oxyethylene unit may be in the main chain, at the terminal, or in the side chain. From the viewpoint of the durability of the effect of preventing the accumulation of static electricity on the surface of the obtained tire and the reduction of electrical resistance, among the compounds having an oxyethylene unit, a compound having an oxyethylene unit at least in a side chain is preferred.

[0160] Examples of compounds having an oxyethylene unit in the main chain include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, monoethylene glycol, diethylene glycol, triethylene glycol, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene alkylamines, polyoxyethylene styrenated alkyl ethers, and polyoxyethylene alkylamides.

[0161] When a compound having an oxyethylene unit at least in the side chain is used, the number of oxyethylene units is preferably 4 or more, more preferably 8 or more, per 100 carbon atoms constituting the main chain. If the number of oxyethylene units is 3 or less, the electrical resistance tends to increase. Also, the number of oxyethylene units is preferably 12 or less, more preferably 10 or less. If the number of oxyethylene units is 13 or more, the compatibility with the rubber component and the reinforcing property tend to decrease.

[0162] When a compound having at least an oxyethylene unit in the side chain is used, the main chain is preferably composed mainly of polyethylene, polypropylene or polystyrene.

[0163] <One aspect of the present invention> In one embodiment of the present invention, the rubber component is (1) Solution-polymerized SBR alone, the molecular terminals of which have been modified with silicon compounds, or (2) A blend containing the above-mentioned terminal-modified solution-polymerized SBR as a main component and at least one rubber selected from the group consisting of unmodified solution-polymerized SBR, emulsion-polymerized SBR, natural rubber and BR as a secondary component. Hereinafter, this embodiment is abbreviated as "embodiment 1."

[0164] In the first embodiment, it is preferable to use a blend of silica as a main component and carbon black as a secondary component as a filler. In addition, in the first embodiment, N,N'-bis(2-methyl-2-nitropropyl)-1,6-hexanediamine (Sumitomo Chemical Co., Ltd. "Sumifine (registered trademark) 1162"), 5-nitroso-8-hydroxyquinoline (NQ-58), bis(3-triethoxysilylpropyl)tetrasulfide (Si-69), bis(3-triethoxysilylpropyl)disulfide (Si-75), 1,6-bis(N,N'-dibenzylthio) It is preferable to use in combination with a viscoelasticity improver such as carbamoyldithio)-hexane ("KA9188" manufactured by Bayer), hexamethylene bisthiosulfate disodium salt dihydrate, 1,3-bis(citraconimidomethyl)benzene ("Perkalink 900" manufactured by Flexis), and alkylphenol-sulfur chloride condensates such as "Tackirol (registered trademark) AP" and "Tackirol (registered trademark) V-200" manufactured by Taoka Chemical. The rubber composition of the embodiment 1 is suitable as a rubber composition for tread members of passenger car tires.

[0165] In one embodiment of the present invention, the rubber composition comprises: (1) 100 parts by weight of emulsion-polymerized styrene-butadiene rubber and / or solution-polymerized styrene-butadiene rubber, (2) 0.1 to 10 parts by mass of a vulcanization accelerator, (3) 5 to 150 parts by mass of CTAB having a surface area of ​​60 to 180 m 2 / g, and the nitrogen adsorption specific surface area is 50 to 300 m 2 / g of silica, and (4) 0.1 to 10 parts by mass of compound (1), The rubber composition of the present invention is obtained by kneading the above. Hereinafter, this embodiment is abbreviated as "embodiment 2". The component amounts of embodiment 2 are values ​​based on 100 parts by mass of the rubber component (i.e., emulsion-polymerized styrene-butadiene rubber and / or solution-polymerized styrene-butadiene rubber). The rubber composition of embodiment 2 can provide a vulcanized rubber composition having excellent abrasion resistance and durability without significantly impairing the viscoelastic properties (fuel economy).

[0166] In one embodiment of the present invention, the rubber composition comprises: (1) 100 parts by mass of diene rubber (e.g., NR, IR, BR, SBR, IIR, halogenated IIR, CR, NBR, etc.) (2) preferably 0.1 to 10 parts by mass, more preferably 0.3 to 3 parts by mass, of compound (1); (3) Preferably, 5 to 150 parts by mass of CTAB have a surface area of ​​60 to 180 m 2 / g, and the nitrogen adsorption specific surface area is 50 to 300 m 2 / g silica, (4) preferably 5 to 25 parts by mass of a resin (e.g., a phenolic resin, a modified phenolic resin, etc.); (5) preferably 5.1 to 7.0 parts by mass of sulfur, (6) preferably 1.0 to 2.0 parts by mass of hexamethylenetetramine, (7) preferably 2.0 to 5.0 parts by mass of a sulfenamide vulcanization accelerator and / or a thiazole vulcanization accelerator, and (8) Preferably, 0.1 to 5 parts by mass of at least one vulcanization accelerator auxiliary selected from the group consisting of alkylphenol-sulfur chloride condensates, organic thiosulfate compounds, and the above-mentioned compound (III). The above-mentioned components are kneaded together to obtain a rubber composition according to the present invention. Hereinafter, this embodiment is abbreviated as "embodiment 3." The amounts of the components in embodiment 3 are values ​​based on 100 parts by mass of the diene rubber.

[0167] The rubber composition of the third embodiment has good processability and gives a vulcanized rubber having excellent abrasion resistance, and is therefore preferably used particularly as a rubber composition for a bead apex and / or a clinch apex.

[0168] <Production of Rubber Composition> The rubber composition of the present invention can be produced by kneading the rubber component, the vulcanization accelerator, silica, and compound (1), and, if necessary, other components.

[0169] The rubber composition of the present invention obtained by further kneading a sulfur component (hereinafter, sometimes referred to as "rubber composition of the present invention containing a sulfur component") can be produced by kneading a rubber component, a vulcanization accelerator, silica, compound (1), a sulfur component, and other components as necessary. The rubber composition of the present invention containing a sulfur component is preferably produced by first kneading a rubber component, a filler such as silica, and other components as necessary (hereinafter, sometimes abbreviated as "step 1"), and then kneading the rubber composition obtained in step 1, the sulfur component, and other components as necessary (hereinafter, sometimes abbreviated as "step 2"). Furthermore, before step 1 (i.e., kneading the rubber component with the filler, etc.), a preliminary kneading step of masticating the rubber component may be provided in order to make the rubber component easier to process.

[0170] In the production of the rubber composition of the present invention containing a sulfur component, the entire amount of compound (1) may be kneaded with the rubber component, etc. in any one of the preliminary kneading step, step 1, or step 2, or compound (1) may be divided and kneaded with the rubber component, etc. in at least two steps, the preliminary kneading step, step 2, etc. Also, compound (1) may be supported in advance on the above-mentioned filler and then kneaded with the rubber component, etc.

[0171] When zinc oxide is compounded, it is preferable to knead it with the rubber component, etc. in step 1. When stearic acid is compounded, it is preferable to knead it with the rubber component, etc. in step 1. When a vulcanization accelerator is compounded, it is preferable to knead it with the rubber component, etc. in step 2. When a peptizer is compounded, it is preferable to knead it with the rubber component, etc. in step 1. When a preliminary kneading step is provided, it is preferable to knead the entire amount of peptizer with the rubber component in the preliminary kneading step, or to separate the peptizer and knead a part of it with the rubber component in both the preliminary kneading step and step 1. When a retarder is compounded, it is preferable to knead it with the rubber component, etc. in step 2.

[0172] For example, an internal mixer including a Banbury mixer, an open type kneader, a pressure kneader, an extruder, an injection molding machine, etc. can be used for the kneading in step 1. The discharge temperature of the rubber composition after kneading in step 1 is preferably 200°C or lower, more preferably 120 to 180°C.

[0173] For example, an open roll, a calendar, etc. can be used for the kneading in step 2. The kneading temperature in step 2 (the temperature of the rubber composition being kneaded) is preferably 60 to 120°C.

[0174] <Production of vulcanized rubber composition> The rubber composition of the present invention containing a sulfur component can be vulcanized to produce a vulcanized rubber composition. The rubber composition of the present invention containing a sulfur component may be processed into a specific shape and then vulcanized to produce a vulcanized rubber composition.

[0175] The vulcanization temperature is preferably 120 to 180° C. Those skilled in the art can appropriately set the vulcanization time depending on the composition of the rubber composition. Vulcanization is usually carried out under normal pressure or under pressure.

[0176] <Application> The rubber composition and vulcanized rubber composition of the present invention are useful for producing various products (e.g., tires, tire components, anti-vibration rubber, rubber for conveyor belts, engine mount rubber, etc.). As such products, tires and tire components are preferred, and tires are more preferred. Examples of tire components include a tire belt component containing the vulcanized rubber composition of the present invention and a steel cord, a tire carcass component containing the vulcanized rubber composition of the present invention and a carcass fiber cord, a tire sidewall component, a tire inner liner component, a tire cap tread component, or a tire under tread component. EXAMPLES

[0177] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples, and can be implemented with appropriate modifications within the scope of the above and following spirit, all of which are included in the technical scope of the present invention.

[0178] The following components were prepared as raw materials for preparing the rubber composition. (Rubber component) SBR: Styrene-butadiene copolymer rubber (manufactured by Zeon Corporation, product name "Nipsol NS616") BR: butadiene rubber (manufactured by JSR Corporation, product name "BR01", cis content: 97.5% by mass)

[0179] (Filler) Silica: (manufactured by Tosoh Silica Corporation, product name "Nipsil (registered trademark) AQ", BET specific surface area: 205 m 2 / g) Carbon black: Carbon black HAF (manufactured by Asahi Carbon Co., Ltd., product name "Asahi #70")

[0180] (Other Ingredients) Vulcanization aid: Zinc oxide (manufactured by Mitsui Mining & Smelting Co., Ltd.) Processing aid: stearic acid (NOF Corporation) Antioxidant: N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (manufactured by Kawauchi Chemical Industry Co., Ltd., product name "ANTAGE 6C") Extension oil: TDAE oil (manufactured by H&R, product name "VivaTec 500") Silane coupling agent: Bis(triethoxysilylpropyl) disulfide (manufactured by EVONIK, product name "Si-75") Vulcanizing agent: Powdered sulfur (manufactured by Hosoi Chemical Industry Co., Ltd., product name "Fine Sulfur S") Vulcanization accelerator (1): N-cyclohexyl-2-benzothiazolyl sulfenamide (CBS) Vulcanization accelerator (2): Diphenyl guanidine (DPG)

[0181] Phosphite ester 1: 300g of cashew oil (Cardolite, NX-2025, cardle rate: 1.8%, methyl cardle rate: 0.9%), 114g (1.11mol) of triethylamine, and 790ml of hexane were charged into a four-necked separable flask, and then 200mL of a hexane solution of 49.1g (0.35mol) of phosphorus trichloride was added dropwise over 50 minutes under a nitrogen atmosphere so that the solution temperature was within the range of 30 to 40°C. After the dropwise addition, the solution was stirred at a solution temperature of 30°C for 4 hours. After the stirring was completed, the solution was washed twice with 0.65L of purified water and once with 0.65L of saturated saline. The obtained organic layer was dried with sodium sulfate, filtered to remove sodium sulfate, concentrated, and dried to prepare 285g of phosphite ester 1. GPC analysis revealed that the monomer ratio of phosphite ester 1 was 88.3%. Phosphite 2: Phosphite 2 was prepared by adding 0.05 g of amine compound A (triisopropanolamine (TIPA, manufactured by Tokyo Chemical Industry Co., Ltd.)) to 50 g of phosphite 1 and heating at 70° C. for 5 minutes to dissolve amine compound A. Phosphite ester 3: Liquid phosphorus-based antioxidant (manufactured by ADDIVANT, product name "WESTON 705")

[0182] Example 1 <Process 1> Using a Banbury mixer (MIXTRON BB-2 mixer manufactured by Kobe Steel, Ltd.), 80 parts by mass of styrene-butadiene copolymer rubber (manufactured by Zeon Corporation, product name "Nipsol NS616"), 20 parts by mass of butadiene rubber (manufactured by JSR Corporation, product name "BR01"), and silica (manufactured by Tosoh Silica Corporation, "Nipsil (registered trademark) AQ", BET specific surface area: 205 m) were mixed. 2A rubber composition was obtained by kneading 75 parts by mass of 100% cellulose acetate / g, 5 parts by mass of carbon black HAF (Asahi Carbon Co., Ltd. "Asahi #70"), 2 parts by mass of stearic acid, 3 parts by mass of zinc oxide, 1.5 parts by mass of antioxidant (N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (6PPD), Kawauchi Chemical Industry Co., Ltd., trade name "ANTAGE 6C"), 30 parts by mass of TDAE oil (H&R Co., Ltd. "VivaTec500"), and 6 parts by mass of a compound capable of bonding with silica (EVONIK Co., Ltd. "Si-75") at a mixer set temperature of 110°C and a mixer rotation speed of 70 rpm. The temperature of the rubber composition at the end of kneading was 150°C.

[0183] <Process 2> The rubber composition obtained in step 1 was kneaded with 2.0 parts by mass of phosphite ester 1, vulcanization accelerators (1.5 parts by mass of N-cyclohexyl-2-benzothiazolylsulfenamide (CBS) and 2.0 parts by mass of diphenyl guanidine (DPG)), and 2.0 parts by mass of powdered sulfur ("Fine Powdered Sulfur" manufactured by Hosoi Chemical Industries, Ltd.) in an open roll machine with a roll setting temperature of 60°C to obtain a rubber composition.

[0184] <Vulcanization> The rubber composition obtained in step 2 was heated at 170° C. for 60 minutes to obtain a vulcanized rubber composition. Such a vulcanized rubber composition is suitable for use in cap treads.

[0185] Example 2 and Comparative Examples 1-2 The vulcanized rubber compositions of Example 2 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the types and amounts of components shown in Table 1 were used in steps 1 and 2.

[0186] [Table 1]

[0187] <Evaluation of filler dispersion> The rubber composition obtained in step 2 was evaluated according to ASTM D8059-16. The filler dispersibility index was calculated as the difference between the dynamic shear storage modulus at 42% strain and the dynamic shear storage modulus at 0.3% strain [(dynamic shear storage modulus at 42% strain)-(dynamic shear storage modulus at 0.3% strain)]. The results are shown in Table 2. The smaller this value, the better the filler dispersibility.

[0188] <Viscosity> In accordance with JIS K 6300-1, the rubber composition obtained in step 2 was evaluated at 130° C. The results are shown in Table 2.

[0189] <Degree of vulcanization test> The 90% vulcanization time (tc(90)) measured in accordance with JIS K 6300-2 is shown in Table 2.

[0190] <Hardness> The measurements were carried out in accordance with JIS-K6253, and the results are shown in Table 2.

[0191] <Tensile properties> Measurements were carried out in accordance with JIS-K6251. Tensile stress (M 100 , M 200 ) was measured using dumbbell No. 3. The results are shown in Table 2.

[0192] <Grip performance evaluation> The viscoelastic properties of the vulcanized rubber compositions obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were measured using a viscoelastic analyzer VR7130 manufactured by Ueshima Seisakusho Co., Ltd., and their loss coefficients (tan δ) at 0°C and 2.5% strain were calculated using the following formula: Fuel efficiency index = 100 × (tan δ of Examples 1 to 2 or Comparative Example 2) / (tan δ of Comparative Example 1) The grip performance indexes of the vulcanized rubber compositions of Examples 1 and 2 and Comparative Example 2 were calculated by the above. The results are shown in Table 2. The higher the index, the better the grip performance.

[0193] <Evaluation of fuel efficiency> The viscoelastic properties of the vulcanized rubber compositions obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were measured using a viscoelastic analyzer VR7130 manufactured by Ueshima Seisakusho Co., Ltd., and their loss coefficients (tan δ) at 60°C and 2.5% strain were calculated using the following formula: Fuel efficiency index = 100 × (tan δ of Comparative Example 1) / (tan δ of Examples 1 to 2 or Comparative Example 2) The fuel economy index of the vulcanized rubber compositions of Examples 1 and 2 and Comparative Example 2 was calculated by the above. The results are shown in Table 2. The higher the index, the better the fuel economy (rolling resistance characteristics).

[0194] <Abrasion resistance evaluation> Using the FPS abrasion tester "AB-2012" (Ueshima Seisakusho Co., Ltd.), the abrasion volume (unit: mm2) of the vulcanized rubber composition was measured in accordance with JIS K6264-2:2005 "Vulcanized rubber and thermoplastic rubber - Determination of abrasion resistance". 3 ) was measured. The FPS abrasion resistance index of the vulcanized rubber composition was calculated by the following formula. The higher this index, the better the FPS abrasion resistance. FPS wear resistance index=(FPS wear volume of Comparative Example 1) / (Examples 1-2 or Comparative Example 2 FPS wear volume) x 100

[0195] [Table 2]

[0196] Example 3 <Process 1> Using a Banbury mixer (600 ml Laboplastomill manufactured by Toyo Seiki Co., Ltd.), 100 parts by mass of styrene-butadiene copolymer rubber SBR#1500 (manufactured by JSR Corporation), 78.4 parts by mass of silica (product name "Ultrasil (registered trademark) VN3-G" manufactured by EVONIK Co., Ltd.), 6.4 parts by mass of carbon black (product name "N-339" manufactured by Mitsubishi Chemical Corporation), 6.4 parts by mass of a silane coupling agent (bis(3-triethoxysilylpropyl)tetrasulfide, product name "Si-69" manufactured by EVONIK Co., Ltd.), 47.6 parts by mass of process oil (product name "NC-140" manufactured by Cosmo Oil Co., Ltd.), 1.5 parts by mass of an antioxidant (N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (6PPD), product name "ANTEGE (registered trademark) 6C" manufactured by Kawaguchi Chemical Co., Ltd.), 2 parts by mass of zinc oxide, 2 parts by mass of stearic acid, and 1 part by mass of phosphite ester were mixed. A rubber composition is obtained by kneading 3 parts by mass (kneading temperature range: 70 to 120° C., mixer rotation speed: 80 rpm for the first 5 minutes after the components are added, and 100 rpm for the next 5 minutes).

[0197] <Process 2> The rubber composition obtained in step 1, 1 part by mass of vulcanization accelerator N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), 1 part by mass of vulcanization accelerator diphenylguanidine (DPG), 1.5 parts by mass of wax (trade name "Sunnock (registered trademark) N" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.), and 1.4 parts by mass of sulfur are kneaded in an open roll machine at a temperature of 30 to 80°C to obtain a rubber composition.

[0198] Example 4 A vulcanized rubber composition is obtained by heat treating the rubber composition obtained in step 2 of Example 3 at 160° C. Such a vulcanized rubber composition is suitable for use in cap treads.

[0199] Example 5 A rubber composition can be obtained in the same manner as in steps 1 and 2 of Example 3, except that a solution-polymerized SBR (Asaprene®, manufactured by Asahi Kasei Chemicals Corporation) is used instead of the styrene-butadiene copolymer rubber SBR#1500 (manufactured by JSR Corporation).

[0200] Example 6 A vulcanized rubber composition is obtained by heat treating the rubber composition obtained in step 2 of Example 5 at 160° C. Such a vulcanized rubber composition is suitable for use in cap treads.

[0201] Example 7 A rubber composition is obtained in the same manner as in steps 1 and 2 of Example 3, except that SBR#1712 (manufactured by JSR Corporation) is used instead of styrene-butadiene copolymer rubber SBR#1500 (manufactured by JSR Corporation), the amount of process oil used is changed to 21 parts by mass, and the timing of adding zinc oxide is changed to step 2.

[0202] Example 8 A vulcanized rubber composition is obtained by heat treating the rubber composition obtained in step 2 of Example 7 at 160° C. Such a vulcanized rubber composition is suitable for use in cap treads.

[0203] Production Example 1: Production of polymerization initiator In a 100 ml pressure vessel in a nitrogen atmosphere, 10 ml of a hexane solution of 1,3-divinylbenzene (1.6 M, manufactured by Tokyo Chemical Industry Co., Ltd.) is added, and 20 ml of a hexane solution of n-butyllithium (1.6 M, manufactured by Wako Pure Chemical Industries, Ltd.) is added dropwise at 0°C. The mixture is stirred for 1 hour to obtain a polymerization initiator solution.

[0204] Production Example 2: Production of diene polymer (modified diene polymer) In a 1000 ml pressure vessel in a nitrogen atmosphere, 600 ml of cyclohexane (manufactured by Tokyo Chemical Industry Co., Ltd., purity 99.5% or more), 0.12 mol of styrene (manufactured by Tokyo Chemical Industry Co., Ltd., purity 99% or more), 0.8 mol of 1,3-butadiene (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.7 mmol of N,N,N',N'-tetramethylethylenediamine (manufactured by Wako Pure Chemical Industries, Ltd.) are added, and 1.5 ml of the polymerization initiator solution obtained in Production Example 1 is added and stirred at 40°C. After 3 hours, 1.0 mmol of tetraglycidyl-1,3-bisaminomethylcyclohexane (manufactured by Wako Pure Chemical Industries, Ltd.) as a modifier is added and stirred. After 1 hour, 3 ml of isopropanol (manufactured by Wako Pure Chemical Industries, Ltd.) is added to terminate the polymerization. After adding 1 g of 2,6-tert-butyl-p-cresol (manufactured by Wako Pure Chemical Industries, Ltd.), the reaction solution is reprecipitated with methanol (manufactured by Kanto Chemical Co., Ltd.) and dried by heating to obtain a diene polymer (a modified diene polymer having two or more modified sites such as terminals).

[0205] Examples 9 to 17 The components other than the sulfur, vulcanization acceleration aid and vulcanization accelerator shown in Table 3 or 4 are kneaded in the amounts shown in Table 3 or 4 at 165°C for 4 minutes using a Banbury mixer to obtain a rubber composition.

[0206] The rubber composition obtained as described above is added with sulfur, vulcanization acceleration aid, and vulcanization accelerator in the amounts shown in Table 3 or 4, and kneaded with an open roll at 80°C for 4 minutes to obtain a rubber composition.

[0207] [Table 3]

[0208] [Table 4]

[0209] The ingredients shown in Tables 3 and 4 are as follows: Phosphite 1: Phosphite 1 used in Example 1 Diene polymer: Polymer obtained in Production Example 2 BR: butadiene rubber (NipolBR1220 manufactured by Zeon Corporation, cis content: 97% by mass) NR: Natural rubber, RSS#3 Silica: EVONIK Ultrasil VN3 (N2SA: 175m 2 / g) Carbon black: Mitsubishi Chemical's "Diablack I" (N220, N2SA: 96m 2 / g, DBP oil absorption: 114ml / 100g) Silane coupling agent: Bis(3-triethoxysilylpropyl) disulfide (EVONIK "Si-75") Zinc oxide: "Zinc Oxide No. 1" manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: NOF Corporation's "Tsubaki" stearic acid Antioxidant: N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (Kawaguchi Chemicals; ANTEGE 6C) Wax: "Sunnock Wax" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Aroma oil: JX Nippon Oil & Energy Corporation "Process X-140" Sulfur: Powdered sulfur manufactured by Karuizawa Sulfur Co., Ltd. Vulcanization accelerator: 1,6-bis(dibenzylthiocarbamoyldithio)hexane ("Vulcuren VP KA9188" manufactured by LANXESS) Vulcanization accelerator (1): N-cyclohexyl-2-benzothiazolyl sulfenamide (CBS) Vulcanization accelerator (2): Diphenyl guanidine (DPG)

[0210] Production Example 3: Production of Polymer 1 The inside of a 20-liter stainless steel polymerization reactor was washed, dried, and purged with dry nitrogen. Then, hexane (specific gravity 0.68 g / cm 3Into the polymerization reaction vessel, 10.2 kg of dimethylformamide, 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran, and 5.0 ml of ethylene glycol diethyl ether are charged. Next, 11.1 mmol of bis(diethylamino)methylvinylsilane and 13.1 mmol of n-butyllithium are charged as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.

[0211] The stirring speed is 130 rpm, the temperature inside the polymerization reactor is 65°C, and the copolymerization of 1,3-butadiene and styrene is carried out for 3 hours while continuously feeding the monomer into the polymerization reactor. The amount of 1,3-butadiene fed in the entire polymerization is 821 g, and the amount of styrene fed is 259 g. Next, the polymer solution is stirred at a stirring speed of 130 rpm, 11.1 mmol of 3-diethylaminopropyltriethoxysilane is added, and the mixture is stirred for 15 minutes. 20 ml of a hexane solution containing 0.54 ml of methanol is added to the polymer solution, and the polymer solution is further stirred for 5 minutes.

[0212] To the polymer solution, 1.8 g of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and 0.9 g of pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) are added, and then polymer 1 is recovered from the polymer solution by steam stripping.

[0213] Production Example 4: Production of Polymer 2 The inside of a 20-liter stainless steel polymerization reactor is washed, dried, and replaced with dry nitrogen, and 10.2 kg of hexane (specific gravity 0.68 g / cm3), 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran, and 5.0 ml of ethylene glycol diethyl ether are charged into the polymerization reactor. Next, 11.0 mmol of bis(diethylamino)methylvinylsilane and 14.3 mmol of n-butyllithium are charged as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.

[0214] The stirring speed is 130 rpm, the temperature inside the polymerization reactor is 65°C, and the copolymerization of 1,3-butadiene and styrene is carried out for 3 hours while continuously feeding the monomers into the polymerization reactor. The amount of 1,3-butadiene fed in the entire polymerization is 821 g, and the amount of styrene fed is 259 g. Next, the polymer solution is stirred at a stirring speed of 130 rpm, 11.0 mmol of 1,3-dimethyl-2-imidazolidinone is added, and the mixture is stirred for 15 minutes. 20 ml of a hexane solution containing 0.54 ml of methanol is added to the polymer solution, and the polymer solution is further stirred for 5 minutes.

[0215] To the polymer solution, 1.8 g of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and 0.9 g of pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) are added, and then polymer 2 is recovered from the polymer solution by steam stripping.

[0216] Production Example 5: Production of Polymer 3 The inside of a 20-liter stainless steel polymerization reactor is washed, dried, and replaced with dry nitrogen, and 10.2 kg of hexane (specific gravity 0.68 g / cm3), 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran, and 5.0 ml of ethylene glycol diethyl ether are charged into the polymerization reactor. Next, 10.5 mmol of bis(diethylamino)methylvinylsilane and 14.9 mmol of n-butyllithium are charged as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.

[0217] The stirring speed is 130 rpm, the temperature inside the polymerization reactor is 65°C, and the copolymerization of 1,3-butadiene and styrene is carried out for 3 hours while continuously feeding the monomers into the polymerization reactor. The amount of 1,3-butadiene fed in the entire polymerization is 821 g, and the amount of styrene fed is 259 g. Next, the polymer solution is stirred at a stirring speed of 130 rpm, 10.5 mmol of N-(3-dimethylaminopropyl)acrylamide is added, and the mixture is stirred for 15 minutes. 20 ml of a hexane solution containing 0.54 ml of methanol is added to the polymer solution, and the polymer solution is further stirred for 5 minutes.

[0218] To the polymer solution, 1.8 g of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and 0.9 g of pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) are added, and then polymer 3 is recovered from the polymer solution by steam stripping.

[0219] Production Example 6: Production of Polymer 4 The inside of a 20-liter stainless steel polymerization reactor was washed, dried, and purged with dry nitrogen. Then, hexane (specific gravity 0.68 g / cm 3 Into the polymerization reaction vessel, 10.2 kg of dimethylformamide, 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran, and 5.0 ml of ethylene glycol diethyl ether are charged. Next, 16.0 mmol of bis(diethylamino)methylvinylsilane and 18.5 mmol of n-butyllithium are charged as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.

[0220] The stirring speed is 130 rpm, the temperature inside the polymerization reactor is 65°C, and the copolymerization of 1,3-butadiene and styrene is carried out for 3 hours while continuously feeding the monomers into the polymerization reactor. The amount of 1,3-butadiene fed in the entire polymerization is 821 g, and the amount of styrene fed is 259 g. Next, the polymer solution is stirred at a stirring speed of 130 rpm, 4.0 mmol of 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate is added, and the mixture is stirred for 15 minutes. 20 ml of a hexane solution containing 0.80 ml of methanol is added to the polymer solution, and the polymer solution is further stirred for 5 minutes.

[0221] To the polymer solution, 1.8 g of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and 0.9 g of pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) are added, and then polymer 4 is recovered from the polymer solution by steam stripping.

[0222] Production Example 7: Production of Polymer 5 The inside of a 20-liter stainless steel polymerization reactor was washed, dried, and purged with dry nitrogen. Then, hexane (specific gravity 0.68 g / cm 3 Into the polymerization reactor are charged 10.2 kg of dimethylformamide, 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran, and 5.0 ml of ethylene glycol diethyl ether. Next, 11.5 mmol of bis(diethylamino)methylvinylsilane and 14.1 mmol of n-butyllithium are charged as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.

[0223] The stirring speed is 130 rpm, the temperature inside the polymerization reactor is 65°C, and the copolymerization of 1,3-butadiene and styrene is carried out for 3 hours while continuously feeding the monomers into the polymerization reactor. The amount of 1,3-butadiene fed in the entire polymerization is 821 g, and the amount of styrene fed is 259 g. Next, the polymer solution is stirred at a stirring speed of 130 rpm, 11.5 mmol of N,N-dimethylformamide dimethyl acetal is added, and the mixture is stirred for 15 minutes. 20 ml of a hexane solution containing 0.54 ml of methanol is added to the polymer solution, and the polymer solution is further stirred for 5 minutes.

[0224] To the polymer solution, 1.8 g of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and 0.9 g of pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) are added, and then polymer 5 is recovered from the polymer solution by steam stripping.

[0225] Production Example 8: Production of Polymer 6 The inside of a 5-liter stainless steel polymerization reactor was washed, dried, and purged with dry nitrogen. Then, hexane (specific gravity 0.68 g / cm 3 ) 2.55 kg, 1,3-butadiene 137 g, styrene 43 g, tetrahydrofuran 1.0 ml, and ethylene glycol diethyl ether 1.0 ml are charged into the polymerization reactor. Next, 3.6 mmol of n-butyl lithium is charged as an n-hexane solution, and copolymerization of 1,3-butadiene and styrene is carried out for 2.5 hours. During polymerization, the stirring speed is 130 rpm, the temperature inside the polymerization reactor is 65 ° C, and monomers are continuously fed into the polymerization reactor. The amount of 1,3-butadiene fed is 169 g, and the amount of styrene fed is 101 g. After the 2.5 hours of polymerization, 11.1 mmol of 3-diethylaminopropyltriethoxysilane is charged into the polymerization reactor as a cyclohexane solution under the conditions of a stirring speed of 130 rpm and a temperature inside the polymerization reactor of 65 ° C, and stirred for 30 minutes. Next, 20 ml of a hexane solution containing 0.14 ml of methanol is charged into the polymerization reactor, and the polymer solution is stirred for 5 minutes.

[0226] To the polymer solution, 1.8 g of 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM) and 0.9 g of pentaerythrityl tetrakis(3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) are added, and then polymer 6 is recovered from the polymer solution by steam stripping.

[0227] Production Examples 9 to 13: Production of Polymers 7 to 11 Polymers 7 to 11 are obtained in the same manner as in Production Examples 3 to 7, except that 11.1 mmol of bis{di(n-butyl)amino}methylvinylsilane is used instead of 11.1 mmol of bis(diethylamino)methylvinylsilane.

[0228] Production Examples 14 to 23: Production of Polymers 12 to 21 Polymers 12 to 21 are obtained in the same manner as in Production Examples 3 to 7, except that the polymer solution is evaporated at room temperature for 24 hours and then dried under reduced pressure at 55° C. for 12 hours instead of steam stripping.

[0229] Examples 18 to 42 The components other than sulfur and the vulcanization accelerator shown in any one of Tables 5 to 9 are kneaded in the amounts shown in any one of Tables 5 to 9 using a 1.7 L Banbury mixer at 150°C for 5 minutes to obtain a rubber composition.

[0230] To the rubber composition obtained as described above, sulfur and a vulcanization accelerator shown in any one of Tables 5 to 9 are added in the amounts shown in any one of Tables 5 to 9, and the mixture is kneaded at 80°C for 5 minutes using an open roll to obtain a rubber composition.

[0231] [Table 5]

[0232] [Table 6]

[0233] [Table 7]

[0234] [Table 8]

[0235] [Table 9]

[0236] The components shown in Tables 5 to 9 are as follows. Phosphite 1: Phosphite 1 used in Example 1 NR(1): Natural rubber, RSS#3 NR(2): Epoxidized natural rubber ("ENR25" manufactured by Kumplan Guthrie Berhad, epoxidization rate: 25 mol%) NR(3): Epoxidized natural rubber (Kumplan Guthrie Berhad "ENR50", epoxidation rate: 50 mol%) BR: Butadiene rubber (Ube Industries "BR150B", cis content: 97% by mass) Polymers 1 to 21: Polymers obtained in Production Examples 3 to 23 Silica: EVONIK Ultrasil VN3-G (N2SA: 175m 2 / g) Silane coupling agent: EVONIK "Si-69" Carbon black: Mitsubishi Chemical's "Diablack N339" (N2SA: 96m 2 / g, DBP oil absorption: 124ml / 100g) Aroma oil: JX Nippon Oil & Energy Corporation "Process X-140" Anti-aging agent: "Antigen 3C" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Stearic acid: NOF Corporation's "Tsubaki" stearic acid Zinc oxide: "Zinc Oxide No. 1" manufactured by Mitsui Mining & Smelting Co., Ltd. Wax: "Sunnock N" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Sulfur: Powdered sulfur manufactured by Tsurumi Chemical Industry Co., Ltd. Vulcanization accelerator (1): N-cyclohexyl-2-benzothiazolyl sulfenamide ("Noccela CZ-G" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Vulcanization accelerator (2): Diphenyl guanidine ("Soxinol D" manufactured by Sumitomo Chemical Co., Ltd.)

[0237] Examples 43 to 46 The components other than the sulfur and vulcanization accelerator shown in Table 10 are mixed in the amounts shown in Table 10 using a 1.7 L Banbury mixer at 150° C. for 5 minutes to obtain a rubber composition.

[0238] The rubber composition obtained as described above is added with sulfur and a vulcanization accelerator shown in Table 10 in the amounts shown in Table 10, and kneaded with an open roll at 80°C for 5 minutes to obtain a rubber composition.

[0239] [Table 10]

[0240] The ingredients shown in Table 10 are as follows: Phosphite 1: Phosphite 1 used in Example 1 E-SBR1: Emulsion-polymerized styrene-butadiene rubber (Nipol 9548 manufactured by Zeon Corporation, styrene content: 37% by mass, Tg: -37°C, oil-extended product containing 37.5 parts by mass of oil per 100 parts by mass of rubber component) Modified S-SBR: Solution-polymerized styrene-butadiene rubber with hydroxyl groups (Asahi Kasei Chemicals' "Tufden E581", styrene content: 37% by mass, Tg: -27°C, oil-extended product containing 37.5 parts by mass of oil per 100 parts by mass of rubber component) S-SBR: Solution-polymerized styrene-butadiene rubber (Nipol NS522 manufactured by Zeon Co., Ltd., styrene content: 39% by mass, Tg: -23°C, oil-extended product containing 37.5 parts by mass of oil per 100 parts by mass of rubber component) NR: Natural rubber, RSS#3 Silica: Solvay "Zeosil 1165MP" Carbon black: Cabot Japan "Show Black N339" Terpene resin: Aromatic modified terpene resin (Yasuhara Chemical's "YS Resin TO125", softening point 125°C) Zinc oxide: "Zinc oxide type 3" manufactured by Seido Chemical Industry Co., Ltd. Stearic acid: NOF Corporation "Beads Stearic Acid YR" Anti-aging agent: Flexis' Santoflex 6PPD Wax: "Sunnock" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Processing aid: "STRUKTOL A50P" manufactured by SCHILL & SEILACHER Gmbh. & CO. Silane coupling agent: Sulfur-containing silane coupling agent (EVONIK "Si-75") Sulfur: Tsurumi Chemical Industry Co., Ltd. "Kinka-in Oil-filled Powdered Sulfur" Vulcanization accelerator: N-cyclohexyl-2-benzothiazolyl sulfenamide (CBS) (Ouchi Shinko Chemical Industry Co., Ltd. "Noccela CZ-G")

[0241] Examples 47 to 51 The components other than sulfur and the vulcanization accelerator shown in Table 11 are kneaded in the amounts shown in Table 11 using a Banbury mixer at 150° C. for 5 minutes to obtain a rubber composition.

[0242] The rubber composition obtained as described above is added with sulfur and a vulcanization accelerator shown in Table 11 in the amounts shown in Table 11, and kneaded with an open roll at 80°C for 3 minutes to obtain a rubber composition.

[0243] The rubber composition obtained as described above is heated at 170° C. for 15 minutes using a press to obtain a vulcanized rubber composition.

[0244] [Table 11]

[0245] The ingredients shown in Table 11 are as follows: Phosphite 1: Phosphite 1 used in Example 1 SBR1: Modified solution-polymerized styrene butadiene rubber (Nipol NS116R manufactured by Zeon Corporation, styrene content: 21% by mass, cis content: 9.5% by mass, vinyl content: 65% by mass, Tg: -25°C, one end modified with N-methylpyrrolidone) SBR2: Solution polymerization styrene butadiene rubber (Nipol 1502 manufactured by Zeon Co., Ltd., styrene content: 23.5% by mass, Tg: -25°C) BR1: butadiene rubber ("BR150B" manufactured by Ube Industries, cis content: 97% by mass, ML1+4 (100°C): 40, 5% by mass toluene solution viscosity at 25°C: 48 cps, Mw / Mn: 3.3, Tg: -104°C) NR: Natural rubber, RSS#3 Silica 1: EVONIK "Ultrasil 360" (CTAB specific surface area: 50 m 2 / g, BET specific surface area: 50m 2 / g, average primary particle size: 38nm, pH: 9.0) Silica 2: Solvay's "Zeosil Premium 200MP" (CTAB specific surface area: 200 m 2 / g, BET specific surface area: 220m 2 / g, average primary particle size: 10 nm, pH: 6.5, aggregate size: 65 nm, D 50 : 4.2 μm, percentage of particles exceeding 18 μm: 1.0 mass%, pore distribution width W: 1.57, diameter Xs giving the pore volume peak value in the pore distribution curve: 21.9 nm) Silica 3: Tosoh Silica "Nipeil E-743" (CTAB specific surface area: 40 m 2 / g, BET specific surface area: 40m 2 / g, average primary particle size: 67nm, pH: 7.8) Carbon black: Cabot Japan's "Show Black N110" (N2SA: 143m 2 / g) Silane coupling agent 1: Bis(3-triethoxysilylpropyl)tetrasulfide (EVONIK "Si-69") Silane coupling agent 2: Momentive's "NXT-Z45" Mineral oil: Idemitsu Kosan's PS-32 (paraffin-based process oil) Resin: α-methylstyrene and styrene copolymer (Eastman "RESIN2336 Hydrocarbon RESIN", softening point: 82-88°C, Mn: 600, Mw: 1250) Stearic acid: NOF Corporation "Paulownia" Zinc oxide: "Zinc oxide type 2" manufactured by Mitsui Mining & Smelting Co., Ltd. Antioxidant: N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine ("Nocrac 6C" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Wax: "Sunnock Wax" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Sulfur: Powdered sulfur manufactured by Tsurumi Chemical Industry Co., Ltd. Vulcanization accelerator BBS: N-tert-butyl-2-benzothiazolyl sulfenamide ("Noccela NS" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Vulcanization accelerator DPG: Diphenyl guanidine (Ouchi Shinko Chemical Industry Co., Ltd. "Noccela D")

[0246] Examples 52 and 53 The components other than the sulfur, vulcanization accelerator, and vulcanization acceleration aid shown in Table 12 are kneaded in the amounts shown in Table 12 at about 150° C. for 5 minutes using a Banbury mixer to obtain a rubber composition.

[0247] The rubber composition obtained as described above is added with sulfur, a vulcanization accelerator, and a vulcanization acceleration aid in the amounts shown in Table 12, and kneaded with a two-screw open roll at about 80°C for 5 minutes to obtain a rubber composition.

[0248] The rubber composition obtained as described above is heated in a press at 150° C. for 35 minutes to obtain a vulcanized rubber composition.

[0249] [Table 12]

[0250] The ingredients shown in Table 12 are as follows: Phosphite 1: Phosphite 1 used in Example 1 SBR: Styrene butadiene rubber (JSR Corporation "SBR1502", styrene content: 23.5% by mass) BR: Butadiene rubber (Ube Industries "BR130B") NR: Natural rubber, RSS#3 Modified diene polymer: Modified styrene butadiene rubber manufactured by Sumitomo Chemical Co., Ltd. (styrene content: 25% by mass, vinyl content: 57% by mass, terminals modified with a compound represented by the following formula (D)) [ka] Vulcanization accelerator: "Takkiroll V200" manufactured by Taoka Chemical Industry Co., Ltd. Modified phenolic resin: Cashew oil modified phenolic resin (Sumitomo Bakelite Co., Ltd. "Sumilite Resin PR12686") Silica: EVONIK Ultrasil VN3 (N2SA: 175m 2 / g) Carbon black: Mitsubishi Chemical's "Diablack I" (ISAF, N220, N2SA: 114m 2 / g) Silane coupling agent: Bis(3-triethoxysilylpropyl)tetrasulfide (EVONIK "Si-69") Oil: Japan Energy "X-140" Stearic acid: NOF Corporation's "Tsubaki" stearic acid Zinc oxide: Zinc oxide produced by Mitsui Mining & Smelting Co., Ltd. Antioxidant: N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine ("Nocrac 6C" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Wax: "OZOACE-0355" manufactured by Nippon Seiro Co., Ltd. Hexamethylenetetramine: "Noccela H" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Sulfur: Insoluble sulfur ("Seimisulfur" manufactured by Nippon Kanretsu Kogyo Co., Ltd.) Vulcanization accelerator 1: N-tert-butyl-2-benzothiazolylsulfenamide ("Noccela NS" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Vulcanization accelerator 2: Diphenyl guanidine ("Noccelaer D" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) [Industrial Applicability]

[0251] The rubber composition and vulcanized rubber composition of the present invention are useful for producing various products (for example, tires, tire components, vibration-proof rubber, rubber for conveyor belts, engine mount rubber, etc.).

Claims

1. A rubber component, a vulcanization accelerator, silica, and a compound represented by the formula (1): 【Chemistry 1】 [In the formula, R １ are each independently -C １５ H ２５－３１ represents a group, R ２ each independently represents a hydrogen atom or a hydroxyl group; R ３ each independently represents a hydrogen atom or a methyl group. A rubber composition comprising a compound represented by the formula:

2. Formula (2): 【Chemistry 2】 [In the formula, R １ are each independently -C １５ H ２５－３１ represents a group, R ２ each independently represents a hydrogen atom or a hydroxyl group; R ３ each independently represents a hydrogen atom or a methyl group; * represents a bond. The rubber composition according to claim 1, further comprising an oligomer (B) having a structure represented by the following formula:

3. The rubber composition according to claim 2, wherein the oligomer (B) has a number average molecular weight of 1,900 to 30,000.

4. The oligomer (B) has the formula (3): 【Chemistry 3】 [In the formula, R １ are each independently -C １５ H ２５－３１ represents a group, R ２ each independently represents a hydrogen atom or a hydroxyl group; R ３ each independently represents a hydrogen atom or a methyl group. The rubber composition according to claim 2, comprising a compound represented by the formula:

5. The oligomer (B) has the formula (4): 【Chemistry 4】 [In the formula, R １ are each independently -C １５ H ２５－３１ represents a group, R ２ each independently represents a hydrogen atom or a hydroxyl group; R ３ each independently represents a hydrogen atom or a methyl group. The rubber composition according to claim 2, comprising a compound represented by the formula:

6. The rubber composition according to claim 1, further comprising an amine compound (A) having a hydroxyalkyl group.

7. The rubber composition according to claim 6, wherein the amine compound (A) is an alkanolamine.

8. The alkanolamine has the formula (I): 【Chemistry 5】 [In formula (I), Y １ , Y ２ and Y ３ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms and at least one hydroxyl group, provided that Y １ ~Y ３ At least one of represents an alkyl group having 1 to 8 carbon atoms and having at least one hydroxyl group. Or, the formula (II): 【Chemistry 6】 [In formula (II), Y ４ , Y ５ , Y ６ and Y ７ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms and at least one hydroxyl group, provided that Y ４ ~Y ７ at least one of represents an alkyl group having 1 to 8 carbon atoms and having at least one hydroxyl group, and B represents an alkylene group having 1 to 4 carbon atoms. The rubber composition according to claim 7, wherein

9. The rubber composition of claim 7 , wherein the alkanolamine is represented by formula (I):

10. Y in formula (I) １ , Y ２ and Y ３ And Y in formula (II) ４ , Y ５ , Y ６ and Y ７ Each independently represents -CH ２ -CH(OH)-R ６ [In the formula, R ６ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

11. The rubber composition according to claim 1 , wherein the rubber component comprises a diene rubber.

12. 2. The rubber composition according to claim 1, wherein the rubber component comprises a styrene-butadiene copolymer rubber.

13. 2. The rubber composition according to claim 1, wherein the vulcanization accelerator comprises a sulfenamide vulcanization accelerator.

14. The rubber composition according to claim 1, further comprising carbon black.

15. The rubber composition according to claim 1, further comprising a sulfur component.

16. A vulcanized rubber composition obtained by vulcanizing the rubber composition according to claim 15.

17. A tire comprising the vulcanized rubber composition of claim 16.

18. In order to improve the abrasion resistance of a vulcanized rubber composition containing silica, a compound represented by the formula (1): 【Chemistry 7】 [In the formula, R １ are each independently -C １５ H ２５－３１ represents a group, R ２ each independently represents a hydrogen atom or a hydroxyl group; R ３ each independently represents a hydrogen atom or a methyl group. Use of a compound represented by the formula:

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